I have personally done this on a S3 LTE and it worked but you do this at your own risk
Just dial the following keys *#197328640#HTML Code:http://forums.redflagdeals.com/free-unlock-samsung-galaxy-s3-note-2-all-gsm-carriers-galaxy-rugby-bell-1266487/
Main Menu > [1] UMTS > [1] Debug Screen > [8] Phone Control > [6] Network Lock > Options [3]Perso SHA256 OFF > (after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in [6] Network Lock then choose [4] NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone