Vizsgara valo felkeszules miatt csak a mai napon tudtam nekiugrani a feladatnak. Az alabbi linken talaltam meg a leggyorsabb megoldast.
http://forum.xda-developers.com/galaxy-s3/development-i9305/warning-gui…
"Recovering IMEI And Data Connection After Flashing WRONG Root Package Intended For I9300:
Make sure you have Samsung Kies or the Samsung USB Driver installed on your PC.
Download and Extract: Odin3 3.04.zip - 457.11 KB to your PC if you don't already have it.
Download and Extract: Param_Bin_I9305.zip - 612.14 KB to your PC.
With your Phone Switched Off, press and hold: 'VOL DN' + 'HOME' + 'POWER' to enter Download Mode.
Connect your phone to your PC via USB Cable and start Odin.
Check your phone is connected by seeing if a COM Port in a Blue box is present under ID:COM.
Press the 'PDA' Button and select the 'Param_Bin_I9305.tar.md5' file you extracted from the Zip Archive earlier.
Press the 'Start' Button and wait for it to finish flashing. If successful, you will see a Green Box with 'PASS!'.
Wait for your phone to reboot then go to your Dialer and press: *#06#. You should now see your IMEI and your Data Connection will be back."
A leiras alapjan 2 perc alatt visszaallt az IMEI.
Koszonom a javaslatokat, uraim!