Q7 MMI system button not working

[Mungo2007]

Hi all 

Had my 2007 Q7 for a couple of weeks lovely car, I do have a few small issues that i need to address. 

First is the MMI system all works perfectly except the SETUP button which does not illuminate when pressed or do anything on the screen, all i want to do is change the clock to the correct time but can't do it. 

I have seen it is fairly easy to remove the switch plate from the centre console, do i need to buy a new micro switch for this can i buy it separately or is it part of the complete MMI switch system. 

Any advice would be great thanks.