Can you give me some insight and information with how you adjust mods.please?

I was using a large handful of the wonderful mods which have been created by you, such as the Travel Cost by CommandDork, Remove Jump Ship Animation by cszolee79, and the Nostalgic Sounds by Conny B to name a few, and due to the recent update, I'd like to edit the mods to the most recent version to be able to use them with it.

I've never created a mod, and only ever adjusted one for GTA IV, which absolutely f* cked the game up to a point where even wiping everything Rockstar off my hard drive, then reinstalling it, didn't get it to work anymore XD

So very Layman's terms-ish please if you would, LOL