Looking for help updating skins/paintjobs for 1.40

I played ATS quite a lot a few years ago, but literally haven't played since. It has been at least two years since I fired up the game. 1.40 is working hard to bring me back to the game, and I'm looking forward to picking up the map packs that have been released since I've been gone.

I used to have a number of custom paint jobs for trailers and trucks that I had just done edits on the graphical parts to make my own stuff. None of those are compatible any more, and I'm not really sure what has changed.

Does anyone know of a simple/easy, or even extremely complicated but still step-by-step process to update these old skins and make them compatible? I'm not sure what has changed in the game to even begin to start figuring out what is out of date in the skin mods.