Find "Change barring password"
Press the Navigation key.
Scroll to Settings and press the Navigation key.
Scroll to Call settings and press the Navigation key.
Scroll to Call barring and press the Navigation key.
Scroll to Change barring password and press the Navigation key.
Change barring password
Key in your current barring password (default is 0000) and press the Navigation key.
Key in a new call barring password and press the Navigation key.
Key in the new barring password again and press the Navigation key.
Exit
Press Disconnect to return to standby mode.