It may be because I upgraded the computer to 'highline'?
Anyway, when stationary, use the rocker switch at the very end of the right stalk (the one that flips through mpg / avge speed / avge mpg / distance to empty / etc) and hold it continually in either the up or down position. After about a three seconds you will enter the Menu screen. Here you can access the myriad of different controls (such as light intensity . coming home lights etc).
If you can't get this then its back to my opening line I'm afraid