4.2 L TDI - MMI power on/off button

[centurion]

hi guys,

i have recently bought a very nice L[ong] 4.2 that has abundance of extras including B&O etc. Now as prev. owner had bought it for himself and later brought in a chauffer to take him places he had disabled [e.g. glued believe it or not] front on/off button so that he was able to control music+volume from the rear centre console.

Question i have is can that switch only be replaced including the housing for the same or do i need to replace whole MMI cluster incl. all other buttons/switches etc?