Did you enable custom art?
Okay...the whole NBA Live wiki is very self explanatory. You should like "really" read it so you can better understand, however, I will give you some information.
First of all, you need to enable custom art because if you haven't nothing that is user-created material will show up. To do this go to the nba live 2003/main/cscripts folder, open xstartup.cfg and replace the last line with this one: customart 1 You may need to open it with Notepad or Notepad ++.
Let me redirect you to a page in this older site for your convenience http://www.sportplanet.com/nbalive/nba2003/custom.shtml