Just installed wm6 to a none working HTC 6700 and now works great, but need to unlock it to assign a number from sprint. Buddy manages a Sprint store and can assign it a number if I can get him the unlock codes.
There is a file floating around called GetSPC.exe that you can run from your 6700 that will do what you want. I can't remeber where I got it from, but it should still be available.