TLDR

1. Follow Steps 1-3 (either Route 1️⃣ or 2️⃣ for Step 3).
2. Play Chapter IV Part 1 in Arcade Mode > Score Attack or New York Minute earning a medal (platinum or otherwise) to get the XP and cash boost.
3. Enter a PUBLIC (not private) multiplayer match in any mode for your new Rank to register properly.
4. (Optional) Progress to the next Legend (prestige status), rinse, repeat if you want to keep progressing (up to 10 more times in total for Legend Ten, Rank 50).

This guide aims at (hopefully) expanding and improving upon the existing guide by Aquilius who deserves a lot of credit for sharing the exploit with the rest of the Steam community:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3044497353
My version of the exploit is meant for solo play in Arcade Mode using Chapter IV Part 1 in Score Attack or New York Minute, depending on your personal preferences and/or availability. The Score Attack version of Chapter IV Part 1 is unlocked as soon as you complete its counterpart in Story Mode, while the New York Minute version is only available if you've completed at least one full playthrough of ALL the chapters in Story Mode on any difficulty. The choice here is up to you.

By employing the exploit, you can earn enough XP to level up from Rank 1 to Rank 50 in a flash and most if not all the cash you'll need to buy everything on offer. While doing so, you may also unlock any of the achievements tied to progression in MP3's multiplayer:

Man Of Many Faces
Unlock All Faction Characters

Man Of Many Weapons
Unlock All Weapons

Training Complete
Achieve Level Rank 50

Normally, each of those unlocks automatically upon reaching Rank 7, 40 and 50 respectively.

I debated long and hard with myself whether I should explore this possibility and share my discoveries with others, for several reasons. For one, long before I even learned about this exploit, I'd already reached Rank 50 in MP3's multiplayer by simply grinding and farming XP, mostly with the invaluable help of my boosting partners. So I wasn't interested in this for my own benefit but that of others, if anything.

Two, the obvious dilemma whether it can be considered cheating. My conclusion is that I, personally, do NOT think it is as it doesn't affect OTHER people in multiplayer, only the person employing this exploit, and in solo play, no less. Sure, using the exploit is bound to give that person an almost instant boost in terms of both the rank and the cash but those offer little to no in-game advantage other than access to more weaponry, equipment and abilities. None of which can be a substitute for skill, however.

And last but not least - and probably the most important consideration, at least for me - this exploit can help others avoid the paynefully tedious grind and save at least 30 hours of their lives that can be spent on other games, or preferably, something other than gaming entirely. And for that reason alone, it think it's worth it :-)

And for what it's worth, I don't NECESSARILY recommend using this exploit. I've tested it myself and can confirm that it works (and like a charm at that) but ultimately, it's between you and your own conscience whether you want to go that route or not. I won't judge you either way.

⚠️Similarly, however, I take NO responsibility for how you decide to proceed with all the information contained within this guide.⚠️

But on the off chance you want to reach Rank 50 by just playing MP3's multiplayer, need help with other online achievements and/or would like to meet some like-minded individuals from Steam, consider joining the Discord server I'm running for those very reasons. If you want in, open your Discord app and click this link >>>[discord.gg]
CU there!

A multi-purpose modding toolset for all the modern Rockstar games going as far back as GTA IV being developed and updated since 2008. It can be used to alter the original files.
Download OpenIV from my Google Drive >>>[drive.google.com]or the official website >>>[openiv.com](may not be secure).

Note: I've checked the file with my own AV software (BitDefender) and VirusTotal (here's the report >>>[www.virustotal.com]) and it SEEMS fine with just one vendor reporting it as malicious, which may be a false positive (or not). So if you have any reservations, don't download or install it. I've personally used OpenIV many times and my own AV software hasn't detected anything suspicious at any point but take this for what it is.

Before you start modding anything, it's HIGHLY recommended that you back up your save data AND any original files you want to alter so that you can restore them to their initial location and state if you mess anything up.

To locate your MP3 save data on Windows, simply copy and paste this address into any of your Windows Explorer address bars and hit Enter: The subfolder inside Profiles is named after your unique Rockstar ID. Copy it to a backup location of your choice.

To locate your MP3 installation folder on Windows, open the Steam desktop app, navigate to your Library tab, right click on the MP3 icon and select Manage > Browse local files. From there, open Max Payne 3 subfolder (henceforth referred to as the root folder that contains the game's executable file, Max Payne3.exe) and back up both of these files:

• common.rpf
  
• update.rpf

Once you've modded any of these files, you can also restore the originals by verifying the integrity of your game files >>> but that would require redownloading them.

Basically, you can follow the steps outlined in Aquilius' guide:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3044497353
If you want an even more detailed guide, refer to section 1️⃣ Edit the original files yourself. If you want an easier method, check section 2️⃣ Drag and drop the premodified files.

First, I'd like to propose a few adjustments to what Aquilius suggests in their guide, however, if only for the sake of keeping the boosted values closer to the ACTUAL ones in case our Rockstar overlords are watching:

1) Instead of 650,000 XP (as suggested by Aquilius), you may want to use 619,500 as this is the ACTUAL amount of XP you'd need normally to reach Rank 50.

2) Instead of boosting your XP reward for earning ONLY the platinum medal upon completing Chapter IV Part I in the New York Minute mode (as suggested by Aquilius), you can do so for the Score Attack mode as well as ALL of the medals: refer to section 1️⃣ Edit the original files yourself points 11.-15. below to learn how.

3) Instead of 250,000 cash for reaching Rank 50 (as suggested by Aquilius), you may want to use 127,500 as this is the ACTUAL amount of cash you'd accumulate normally by going all the way up the ranks.

Note: when editing the files, make sure to use numbers WITHOUT any decimal separators, so 619500 and NOT 619,500, for example.

1. Run OpenIV.

2. Select Max Payne 3 (Windows), prompting OpenIV to load the game's assets.



3. Once the assets are loaded, click on Edit Mode towards the top of the window (or press F6).



4. Confirm your selection by clicking "Yes" in the pop-up window (or press Enter).



5. In the directory tree on the left hand side of the window, DOUBLE click on common.rpf to open it.



6. Now click on data just below.



7. From the list of files on the right hand side, select rank.csv.



8. Right click on it and from the menu select Edit (or press Ctrl+Enter when the file is selected by left clicking on it).



9. In the new window (OpenIV Text editor), scroll down to line 148.



10. Edit it by replacing the number 5000 with the amount you want to receive upon reaching Rank 50 (127500 is recommended). Or you can simply replace (copy/paste over) the whole line with:

⚠️The amount of cash you'll need to afford every single piece of equipment available in the game is 218,300 so you MAY want to use that number instead (without the digit group separator so 218300), unless you've already progressed to a Legend prestige status and have access to the Badge of Honor gear that boosts your cash rewards and have it equipped in your current loadout.⚠️

Click on the Save icon to apply the changes.



11. In the directory tree again, DOUBLE click on update.rpf.



12. Navigate through common > data > tune all the way to arcade (similarly to what we did in point 6.) and select arcademodesettings.xml to edit it (like we did in point 8. with the previous file).



13. In the new window (OpenIV Text editor), scroll down to line 136 for the Score Attack values or line 137 for the New York Minute values, depending on which of these Arcade modes you prefer to play and/or have access to.




14. In either (or both) of these lines edit any of the settings corresponding to XP rewards for different medals: bronzeXP=, silverXP=, goldXP= and/or platXP= (with XP in their names) by replacing the number between the double quotation marks with the amount of XP you want to get by earning any of those medals (619500 is recommended).

⚠️You can enter a different number here but be careful: do NOT go overboard with it as too high a boost - especially if applied at once - may not register properly and lock you out from earning any XP legitimately and thus progressing in your Rank and Legend status. You need exactly 6,814,500, or 619,500 x 11 for all eleven full progressions from Rank 1 to 50, all the way up to Legend 10 Rank 50.

Be especially careful if you're applying the boost for the Training Complete achievement awarded for reaching Rank 50. To be safe, boost your XP just enough for Rank 50 (so by no more than 619,500), enter a PUBLIC multiplayer match for it to register properly and only then progress to the next Legend rank if you want to.

If you DID go overboard despite the warning, fear not: you can actually subtract your XP by entering a negative number in line 137 (e.g. -619500) and then earning a medal and entering a public multiplayer match for the changes to register properly.⚠️

If you want to boost your XP rewards for ALL of the medals, you can simply replace (copy/paste over) the whole lines with the codes below.

For Score Attack:


For New York Minute:




15. Once you've edited the values to your liking, click on the Save icon to apply the changes.



And with that, you're all set!

Alternatively, you can download one of these archives containing the PREmodified files I've prepared with the abovementioned adjustments:

• one with the boosted amount of XP awarded ONLY by earning the platinum medal for Chapter IV Part 1 in New York Minute (as originally suggested by Aquilius): download from my Google Drive here >>>[drive.google.com]
  
• one with the boosted amount of XP awarded by earning ANY of the medals for Chapter IV Part 1 in New York Minute: download from my Google Drive here >>>[drive.google.com]
  
• one with the boosted amount of XP awarded by earning ANY of the medals for Chapter IV Part 1 in Score Attack: download from my Google Drive here >>>[drive.google.com]
  
• one with the boosted amount of XP awarded by earning ANY of the medals for Chapter IV Part 1 in BOTH New York Minute and Score Attack: download from my Google Drive here >>>[drive.google.com]

The other file - shared between all of these archives - will earn you the adjusted amount of cash (127,500) upon reaching Rank 50.

With those PREmodified files downloaded and unpacked, you can simply drag and drop them into their respective locations to replace the original files using OpenIV:

• rank.csv = common.rpf > data
  
• arcademodesettings.xml = update.rpf > common > data > tune > arcade

Easy-peasy!

Now all you need to do is complete Chapter IV Part I in the Score Attack or New York Minute mode and earn the necessary medal (either the platinum or any of the medals), depending on your choices in the previous step.

The Man of Many Weapons achievement should pop as soon as you finish the chapter if you didn't have it already. In order to unlock Training Complete, however, you need to enter a PUBLIC multiplayer match for it to register properly.

If you want to continue rising through the ranks, you may elect to walk away from your current one and start over as Legend One, gaining a kind of a prestige status. Note: If you do that, you'll lose your current rank, weapons, upgrades and cash. But you can easily get them all back by completing Chapter IV Part I in the Score Attack/New York Minute mode again to earn the boosted XP and cash.

Do this 11 times in total and you'll go all the way to Legend Ten/Rank 50, the highest possible rank in MP3 multiplayer: