Udate Droid 2 to gingerbread without losing Metro flash


Hello I have a droid 2 I had flashed to Metro PCS. I want to update to gingerbread. Maybe CM7. My question is how to do that without losing my flash. I've done some searching and will continue to do more. I'm just short on time right now. Could anyone help me or point me in the right direction. I do have some experience with droid.