It seems that the actual requirement for the achievement is to see Kim in his black jacket, which is unlocked after beating the game in Hardcore mode. The Pissf****t jacket is not needed in any way.

So the obvious solution is to beat the game in Hardcore.

However, if you don't want to / did it already / lost your save - there is a way to get around that:

1. Go to "C:\Users\*UserName*\AppData\LocalLow\ZAUM Studio\Disco Elysium\Settings\"
2. Open Settings.json with Notepad or something.
3. Find "hardcore_playthrough_completed" section at the bottom.
4. Change "boolValue" from false to true and save changes.
5. Launch the game, load any save with Kim, toggle Hardcore mode on.
6. Done!
P.S.
You can return Kim his orange jacket by changing "boolValue" back to false.