1. 1. Find "SIM card lock"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press Password & security.
Press System security.
Press SIM card lock.
2. 2. Turn use of PIN on or off
Press the required SIM.
Press the indicator next to "Lock SIM Card" to turn the function on or off.
Key in your PIN and press the confirm icon.
3. 3. Return to the home screen
Press the Home key to return to the home screen.