Lol well, I'm a ma'am, but I can still help.
Check out this thread -
http://forum.ppcgeeks.com/showthread.php?t=43266
Judging by the fact that it was already flashed, it should probably already be unlocked, so you should just be able to download the ROM you want & flash it. May I recommend any of Mighty Mike's ROMs, I'm on 4.16 & I love it.