try this ::
go to the system tab slect console settings go down to system info click on it then press this in order
LT RT X then Y LB RB X then press the directional pad left right left
you will then see a screen to reset your settings
If it doesn't work right away, just try it again. A screen should pop up asking you if you would like to reset the settings. This won't delete your profile or anything so select YES. The XBOX will restart itself and it will then ask for the language and country again. Next it will ask for info on the pass code. Choose the rating you want the code for and then input your new code.