Find "change password"
Press arrow right to access the main menu.
Press Settings.
Press lock & wallpaper.
Press change password.
Change phone lock code
Key in your current phone lock code.
Press the field below New password and key in a new phone lock code.
Press the field below New password and key in a new phone lock code.
Press the field below Confirm password and key in the new phone lock code again.
Press done.
Exit
Press the Home key to return to standby mode.