A begginer's adventure into custom skins.

I am interested in creating a custom skin for a champion. I am familar with modeling within Maya, I am however knew to the texturing side. I am in sophmore year in college for game development and have a project for concept art. Figured creating a custom skin would be a fun project! Just a couple base questions such as;

1. Are champion models still available through our client folder? (Currently in class, no access to my rig.)

2. What is the process for reskinning animations?

3. What is some awesome freeware for texturing / file conversion?

4. Is any of this even allowed or is this one of those EULA breakers?

TL;DR: WANT TO MAKE SKIN, PLZ HELP.