garyangi:
You cannot flash another GDFS to your phone, and the IMEI cannot be changed by hand. You can try to repair your GDFS with SEMCTool v8.7 cracked, but use it at your own risk: SemcTool v8.7 Cracked
vejendla:
Check out the first post of this thread, and read the tutorial(the DB2020 part). You said that you debranded the phone, so you must have the MAIN firmware. Follow the tutorial carefully, and do not skip anything, because there aren't pointless steps.