Hmm I am not sure if I am qualified to give that kind of advise. There is an entire thread on it and I imagine someone will have the link though I think its a sticky under the apache section. "basically"
Download the "kitchen" build OS thingy install it. Make sure active sync is installed and working. Open the kitchen program let it run its updates etc.. then pick that helmi default options txt file for starters leave everything stock just make sure A2DP is selected. under bluetooh and hit the ply button. it will do a bunch of stuff and then it will flash your phone. Just make sure NOTHING disturbs this process
If it ends up being not so good you can alwys go back (get the download from HTC the 2.2 update is a full OS flash and will bring you back to sprint stock.
BT Contacts transfer does NOT work in 6.1 so make sure you backup your contacts first either on the SD or with active sync