Please see the first post in this thread. However you are better off staying at 4.5 on the 8330.
5.0 has a real back memory leak.. I mean real back. I really can't fathom how a carrier releases this OS.
8830 -> 8330 -> 9550 -> 9650
Just think about how far BlackBerries have come from then till now... And what else is coming.
Follow me on Twitter