If you would like to change the SIM pin code, start from the next step.
If you would like to set up a lock screen on your phone, jump to step 11.
Make sure you have your Public SIM PIN before you start the guide.
Scroll to and select Security
Scroll to and select SIM card lock
Select Public and Change SIM PIN
Enter your Old SIM PIN and select OK
Enter your New SIM PIN and select OK
Confirm your new SIM PIN and select OK
Your SIM PIN has been changed
To activate your screen lock, go to the Settings menu and select Security