Process:
Stage 1
1) Reboot into recovery. Check your current recovery version. If you have CWMT or MultiBoot you will need to change it, or this WILL brick your phone. Use Flash Image GUI (or the BACKside updater if you're running BACKside - thanks Jerry, you rock!) to flash Bobzhome's recovery.
2) Go to Backup and Restore, choose Backup.
3) Once done, click back to the main menu. Choose apply update from sd.
4) Once that is done, choose reboot system now.
5) Your phone may or may not boot at this point - don't panic! If it doesn't boot, just pull the battery, then boot back into recovery. If it did boot up, reboot into recovery anyway!
6) Choose factory reset/wipe data.
7) Choose apply update from sd (yes, again.)
8) Once done, reboot to system.
9) The phone should boot up to the stock rom. You can verify the radio version now by Menu-Settings-About Phone-Baseband Version. It should end in ZV9. If not, stop. Return to step 3, and repeat.