How to lock certain options in the quick menu?

You can lock certain options in the quick menu so the customer cannot adjust for example the sound, brightness, freeze ect. 
When they are locked the buttons will be greyed out. 

To lock these buttons go to the dealer menu. (you can enter this via the code on the remote which should be known to all dealers)
Under the menu settings you will find an overview to lock the desired button in the quick start menu.