How to save custom jerseys?

I downloaded this jersey template:

http://download.nba-live.com/pafiledb.p ... ile&id=133

What next? Should I load 1.png, add a logo and colors? How should I save it?

Also another question this related, how to make jerseys?

I would like to play with more than one home and one away jersey. Seattle and Phoenix had cool jerseys in the 90s and they are in the game. Unfortunately, the Knicks only have some boring ones. That's why I want to create fictional jerseys for New York.