Hey there!
In order to mod your game first things first is to get to the folder containing your game.
If you got the game from Steam it should be somewhere along the lines of:
Program Files (x86)\Steam\steamapps\common\Fear & Hunger 2 Termina
I think it's easier with itch.io since they give you the whole folder already so you can find it much easier.
If you now have access to the game folder the next step is to download the TY_ModLoader.js file and open it in a program like notepad.
This file is used to tell the game what mods to load, but the most important part is that it also contains a tutorial in how you should set up your mods.
Let me know if you managed to get the mods working on your side.
Cheers!