Samsung Galaxy Note 10.1
Find "Change password"
Press the menu icon.
Press Phone.
Press the menu icon.
Press Call settings.
Press Additional settings.
Press Call barring.
Press Voice call.
Press the menu icon.
Press Change password.
Change barring password
Press Old password and key in your current barring password (default is 0000).
Press New password and key in a new barring password.
Press Confirm password and key in the new barring password again.
Press OK.
Exit
Press the home icon to return to standby mode.