Find "Keyguard code"
Press the Navigation key.
Scroll to Settings and press the Navigation key.
Scroll to Phone settings and press the Navigation key.
Scroll to Keyguard settings and press the Navigation key.
Scroll to Keyguard code and press the Navigation key.
Turn use of phone lock code on or off
Key in the phone lock code (default is 12345) and press the Navigation key.
Highlight On or Off and press the Navigation key to turn this function on or off.
Return to the home screen
Press Disconnect to return to the home screen.