Automatic Gear Box Selector

I dont know whether I have moved something slightly when over zealously polishing the auto gear selector (although I doubt it) but in PARK and 1st the light comes on and then goes off and sometimes then PARK fails. Its obviously not clicking in correctly and sometimes only needs a slight wiggle on the stick and it realights.

Had to have work done at a garage recently underneath with some leaking seals and that has now been resolved (but they now claim that would not affect this problem now as the switches go and its another "common fault")

Its still driveable for time being and just using handbrake when parking on hills whilst driving but also noticed the reverse sensor now doesnt come on automatically when reverse is engaged.

Taken the cover off and found a pound coin in there bizarelly enough and tried clicking the casing on properly but somehow I think this is more of a fault than something I can fix easily??

There are two capless bulbs in the selector one ether side they some times work lose so only need to be pushed back to make contact and the cable to the reverse switch has been pulled off, maybe.

How do I take cover off completly. I am guessing there is a small electrical box connection holding it on at bottom near Gear 1? Think I need to get one of those CD roms showing how to pull stuff apart. Think something is holding it on near Sport Mode Button

U can't unless u remover the T handle.. Sounds like u have a D2 but on a D1 u have to unclip the display panel at the rear edge and then release the front clips lift the panel slightly and pull the matting away to see the bulb and it's holder each side.. It's fiddly took me half hour to replace the two bulbs that had blown. A Haynes manual does me fine they now do one for a D2.