Step 3. Choose “UMTS”.
Step 4. Next choose “Debug screen”.
Step 5. Choose “Phone Control”.
Step 6. Choose “Network Lock”.
Step 7. Choose “Perso SHA256 OFF” and wait about 30 seconds.
Step 8. Press the Menu button then choose “Back”.
Step 9. Choose “NW Lock NV Data Initiallize” and wait about 1 minute. Then reboot your Note 2.
Step 10. Once rebooted, you should no longer get the Network Lock window anymore and you should be able to get signal and data. If you have trouble getting 3G/HSPA+ data, try setting the APN to your carrier’s settings although it should set automatically.
If you are on Android 4.1.2, try installing Phone Utility to access the menus or reflash Android 4.1.1 ROM to unlock (then revert back to 4.1.2 once unlocked)