Use at own risk. I don't take responsibility for anything.
Had this guide now for a while in my unpublished guides. Don't know why i didn't publish it, most likely i wanted to polish it some more. But i don't know when i will go back to this game, so i'm just gonna publish it, in its current state as-it-is. Somethings might be wrong, something might have changed, but maybe it helps some people.

Edit: There seems to be a new version of the motmod addon by camebridge spy - since i don't have tested it i don't know if any changes to the guide are required when using the newest version instead of version 13 as described in the guide. More info on the latest version here https://psteamcommunity.yuanyoumao.com/app/34410/discussions/0/3830917450447521567/

Get a full version of Death to Spies (DtS)
Download master branch https://github.com/forlik/motmod
Download https://www.dropbox.com/s/2fb4i5xemdva9rc/MOTMOD_ADDON_BY_CAMBRIDGE_SPY_V13.0.rar?dl=0

Install DtS and install DtS: Moment of Truth (DtSMoT). Do not start anything yet.

In case you have already tried starting DtSMoT you should see the config folder %USERPROFILE%\Documents\My Games\Smersh_MT leave it as it is for now, but remember it.

Next up, go into the installation directory of DtS and run smershSetup.exe
Configure full-screen, full-hd, v-sync, triple buffering, software sound, max graphic settings.
Save, apply & exit - now start smersh.exe or launch it via steam. Create a Profile, save and exit.

Great DtS works but why did we fix DtS and not DtSMoD? Well keep reading and find out...

Extract motmod-master.zip
Open the folder, switch to tools and run VfsTool.exe

Click on Open, navigate to install directory of DtS and select one of the .vfs files
It is important that you only open one file at a time.

1. Click on "Open" select "Levels.vfs" for example
2. then click on Save All and select the DtSMoT directory
(or create a empty directory to store the files and copy them later and to keep a copy of patched files so you don't have to repeat the whole process whenever you do a fresh installation)
3. Wait for the program to finish (green bar at max, might lag for a few seconds on some files, just wait for it)
4. Click "Close" to close the .vfs file - now repeat the whole process with the next .vfs file

You need to extract the following files with the tool
Levels
Models
Players
Scripts
Sounds
Textures
UI
Shaders


Now - repeat the same with the files from DtSMoT, and save them to the DtSMot directory (or whatever directory you have used), overwrite existing files.

Important, if you don't follow the extraction order you need to make sure not to overwrite DtSMoT files with DtS ones. Thats why we started with DtS first. Same applies to the other files. If you install MOTMOD_ADDON_BY_CAMBRIDGE_SPY first you will have problems selecting and overwriting the files. Its basically in logical order . Oldes files get extracted first, and newer ones overwrite them. Therfore DtS, DtSMoT, MOTMOD Spy and then MoTmodAddonFarClipFix.

Next, extract MOTMOD_ADDON_BY_CAMBRIDGE_SPY_V13.0.rar
copy all folders from inside the folder "MOTMOD_ADDON_BY_CAMBRIDGE_SPY" into DtSMoT directory, overwrite any existing files.

switch to the "MoTmodAddonFarClipFix" and copy the levels folder into the DtsMoT directory.

Now, launch TruthSetup.exe from DtsMoT directory

i don't know why, but everyone is referring to smashsetup.exe - which is the .exe for DtS...which is kinda weird considering that all guides are for patching DtSMoT and you wan't to patch the newer game and not the older one... but anyways.. lets continue

Moment of truth..(literally). Does it launch the options window? Or do you get Error 5?
if it launches then youre all set - configure the same options as for DtS (full screen, fullhd, v-sync ,triple buffering, etc, etc). Enjoy your game. Launch Truth.exe or launch from steam.

Well if it does not work we can use trick 17.

Go to %USERPROFILE%\Documents\My Games\
Do you have a directory called Smersh_MT? yes? Good. If not try launching the game / game options a few times until it appears.
You already have it? Great. Some people say you can delete it and its corrupt, but if you can't even launch the options... then the defaults are already corrupt. and deleting it won't help at all. But hey, here comes trick 17 - you see the Death to Spies directory? Remember we created a Profile in DtS? Good that you didn't skipped that part. Copy all Files / folders from the %USERPROFILE%\Documents\My Games\Death To Spies\ directory to
%USERPROFILE%\Documents\My Games\Smersh_MT\Profiles


And done. Mission Complete. If you launch TruthSetup.exe the options window should finally show up. But there is not much to configure, as we already configured options in DtS. So now Start the game. Oh and don't forget to uninstall DtS - you can play all missions now in DtSMoD - both in one game.

For anyone asking to share the DtS files: NO, get the ♥♥♥♥♥♥♥♥ game for 5€ (actually i payed only 2,62€ for both games..) and extract the files more or less legally for your own personal use. Sharing them is illegal!

https://www.pcgamingwiki.com/wiki/Death_to_Spies

https://www.pcgamingwiki.com/wiki/Death_to_Spies:_Moment_of_Truth

https://sites.google.com/site/adventurewalkthroughs/dts

https://sites.google.com/site/adventurewalkthroughs/dtsmot

https://psteamcommunity.yuanyoumao.com/app/9800/discussions/0/558749825304425179/#c617330406658094110
https://psteamcommunity.yuanyoumao.com/app/9800/discussions/0/523898291493897984/
https://psteamcommunity.yuanyoumao.com/app/34410/discussions/0/610574106418689231/
https://int0thegame.blogspot.com/2008/11/death-to-spies-extractor-101.html