Mods from steam

[black1]

Hello all, I downloaded my game from GOG galaxy which also updates the game and I was wondering if anyone else uses mods but does not use steam, I want to use a few mods but don't know how to or where to place them if this if even possible.

I did not DL from steam so if there are others who did not use steam and do use mods please tell me how to go about this, thank you all.