Association Problem ... tsktsk

there have been too much players on my bulls team and i can't release or put the players on the d league. It tells "Cannot be more than 15 players" ... what should i do, i oversigned rookies? and please tell me the png number of kobe in my team.. here's the url.

http://www.mediafire.com/?t7kmd4zr1o5g461

NEEDED ASAP! THANKS