How to mod an existing character?

[ZarephLae]

I tried looking this up and doing research but I couldn't really find anything. My plan is to make a modified version of Webber that makes more sense to his monster side.

For starters, he would have night-vision to see in the dark since the spiders in the game can see in the dark. This would make it so he doesn't get hurt by the darkness which makes sense to me but in exchange, I want to swap around his sanity. So he doesn't lose any during the night but does during the night.

If anyone has a tutorial or resources I can follow, I'd be appreciative.

[Leonidas IV]

Try looking at the code of a mod that changes a character.