If you forgot your password for this feature, press the following buttons on the remote, one at a time. (Note: You must be in the password entry screen) Press, Mute, Display,Clear and Reset, this unlocks parental controls and you can now re-enter a new password.
OR TRY THIS..
Press and hold Menu on the TV AND volume down on the remote for 3 seconds. Nothing will appear on the screen, and the Parental Controls will unlock, and you can re-enter a new password with the LOCK PARENTAL CONTROLS