The first golden skeleton is in Afia's "Blink" tutorial. After you teleport past the first set of guards and climb the vines, teleport under the bow of the floating ship and blink again through the cracks of the boards.

In the "Shadow Step" tutorial, progress until you've past through the torii. Move Toya close enough to toss down the talisman and teleport to it.

At the very end of the "Wander Dust" tutorial, you'll see a floating platform the skeleton on it. I killed it before I started taking screenshots for this guide, but it's about where I threw the cover seeds. You'll need to hit the skeleton with the dust, run over to the canon, and shoot it.

In Teresa's "Iron Judgment" tutorial, clear to the end. Click on the floating platform around the side of the tower to make her move, then snipe the skeleton from your better vantage point.

After killing the first enemy in the "The Below" tutorial, move John near the wall and anchor down.










Swivel the camera around to see a hidden platform and kill the skeleton (skelly not pictured bc I already got em)

In Quentin's Challenge Room, clear the room with the two big boxes and make a quick save. Maneuver him to the smashed wall as pictured, and throw down your head. The golden skeleton will walk over to it, so quickly reel it up and stab the rotten skelly for being so greedy.

(Outdated) This is where I have to admit that I am not a pro-gamer who's 100% the game in 4 days. Apologies.
I do not know how to kill the next two golden skeletons.
In Gaelle's Challenge Room, it looks like you're supposed to use firecrackers to bait the skeleton to a spot where you can rope it up like in Quentin's room, but the skeleton just looks blankly at the explosion. If you figure this one out, tell people in the comments. I'm too lazy to update a guide I've already published.

(Real answer) I don't have a screenshot for this part because I've already uninstalled the game, but this skelly was moved in a patch. Check the comments for a guide

(Outdated) This is the other one I haven't killed. In Pinkus' "Coin" tutorial, the skeleton is on a small, floating platform that appears to be impossible to reach. If the guards you posses were able to shoot, it would be simple, but for now, I don't know how it would be possible to kill this one.

(Real answer) There is a floating cannon that for some reason will fire when a coin is thrown at it, killing the skeleton.











And with that, I've given a mostly complete guide to every golden skeleton. Thank you to the comments for finding the last two. If you're itching for more Mimimi-esque content, check out Sumerian Six, and have a nice day.
A presto.