Hello, ashrond. I had the exact same problem as you did a few day ago, so I can be of some assistance. As far as I know, no one felt like posting the tutorials on it, so I will show you how to extract them.

First thing you should do is get a REZ extractor. 7Zip should do, and if you don't have that, you may also use WinRez LT Studio. Both work wonderfully.

Second thing to do is go into your Tron 2.0 folder, and then search for the files you want. There is 6 REZ files, which I will list.
Engine.REZ,
game2.REZ,
Game.REZ,
gamep5.REZ,
gamep6.REZ,
and finally, Sound.REZ.
They all have different files, however, I am not sure which contains skins and/or models. But they are in there.

That is all you need to to to obtain the models and skins you need. Good luck on your modding.