itch.io

First, go where you game are and make a copy of your save in another place...just to be safe.

(I recommend using winrar to do that :3)

Then, just open where the game.exe are and put the all archives from the mod there.

(It must have one called www)

And replace that archives with the mod ones.

You can starts a new game to test and a new mensagem will appear, telling about the mod