Carrier Unlock Method for the Galaxy S3 and Galaxy Note 2 Running Jelly Bean, Running in the Wirld
Considering how many Galaxy S3′s and Note 2′s Samsung has sold already, it’s pretty likely that you, or someone you know, has one or the other. And now there is a carrier unlock method out in the wild. This will allow you to unlock your device and run it on another carrier. But this will not work for Galaxy S3′s or Galaxy Note 2′s on Verizon, Sprint or any other CDMA carrier. As those models will only work on that particular carrier. And this unlock is only for GSM carriers (i.e. AT&T, T-Mobile, and others worldwide)
Now it’s important to let everyone know that we do not support this procedure, so if anything goes wrong it’s on you. Now that you understand that we are not responsible for damage caused to your device, let’s go ahead with the instructions from Redmond Pie on unlocking your device:
Step 1: On your Galaxy Note II, launch the phone app and press these keys:
Step 2: From the Main Menu, navigate to  UMTS > Debug Screen >  Phone Control >  Network Lock > Options.
Step 3: In the Options screen, choose  Perso SHA256 OFF. Wait for 30 seconds after making this selection.
Step 4: Go back one step by pressing the menu key, and then back once. You should now again be in  Network Lock
Step 5: Here, now choose NW Lock NV Data INITIALLIZ. Wait for one minute after making the choice.
Step 6: After a minute has passed, reboot your Galaxy Note II.
Also, XDA forum member owl74 found out there is a hidden menu in Touchwiz which will allow you to unlock your device from your own home. This method is confirmed working on the GT-N7105, but should work on other Galaxy S3 and Note 2 models. You can find out more information from the source below.
So who’s ready to take the plunge and unlock their Galaxy S3, or Galaxy Note 2? If you are brave enough to unlock your device, let us know in the comments below how well or not so well it worked for you.