This can be flashed onto ANY phone regardless of existing firmware (Custom, stock, EPE, EPF etc) - The only requirement is that your phone have an unlocked bootloader and ideally AmonRa's recovery menu. Check the pinned topics if you're not already at this stage (you should be!)
If it doesn't work, then you've missed something - wipe everything and flash again.
1. Copy Paul's pre-rooted FroYo FRF50 update.zip with radio from HERE to the root of your SD Card. (Use the one without radio if you've already got the FroYo radio)
2. Boot into recovery (Preferably at least Amon Ra 1.6.2 or newer/equivalent)
3. Make a nandroid backup (+ext if you use it)
4. Wipe data+cache, Battery Stats and Rotate settings (You might be able to get away with not doing this, but it's doubtful)
5. Flash Paul's Pre-Rooted FroYo ROM.
7. Wait for the radio update to finish & return to recovery. (If it says "formatting cache" - ignore it and continue)
8. Reboot again.
9. Enjoy 2.2.
To return to a stock (but rooted) 2.1 ROM replace steps 1. & 5. with these steps instead:
1. Download the EPF21B update.zip from here and copy that to the root of the SD card too.
5. Flash the EPF21B update.
If you need the FroYo radio (v4.06) by itself (to flash with fastboot flash radio radio-32.36.00.28U_4.06.00.02_2.img) then you can get it from here
if you want a 2.1 radio then get it from here (v4.04) - This can be applied via Recovery, or you can extract the .IMG and flash it with fastboot.
Edited by stevenz, 11 June 2010 - 05:50 AM.