1. To lock the device, press the Power/Lock key.
   
2. To unlock the device, press the Power/Lock key.
   
3. Swipe up to unlock the device.
   
4. To set a password on your device, swipe down from the Notifications bar.
   
5. Tap ALL SETTINGS.
   
6. Scroll to, then tap lock screen.
   
7. Toggle Password On to create a password.
   
8. To set the password for your phone, type at least a Four-digit password into the fields, then tap done.
   
9. Your password is now active.
   
10. To access your phone after the password is active, swipe up from the Lock screen.
    
11. Enter your Password to unlock the device.
    
12. To change the password for the device, from the lock screen menu, tap change password.
    
13. Enter your current password, the desired new password twice, then tap done.
    
14. To remove a password from the device, from the Lock Screen menu, toggle the Password setting off.
    
15. You will be prompted to re-enter your Password.
    
16. The feature is now off.
    Note: To learn more about requesting a device unlock for your AT&T mobile device, visit www.att.com/deviceunlock. If your device is locked and is requesting a "PUK" code, click here for instructions on how to obtain your PUK or PUK2 code to unlock your SIM card.