You can do it, but first you need to unlock it; go here
http://forum.ppcgeeks.com/showthread.php?t=24979 remember, DO NOT LET CUSTIMIZATIONS RUN!!!!!
My experience with Bell is to go with either NFSFANs, GHETTOFREERIDER or WhosDaMans custom Bell ROMS, they work, othe generic ones don't work perfect. Make sure you get the bell ppst.exe too.