As the switch is stuck down, it appears it is knackered. They re cheap to buy. If you can't get in with the small screwdriver to the plastic spring loaded latch, then remove the instrument bezel, push the switch out and remove the plug from the rear of the switch and use a short length of wire in the plug pins to jump it out.
Tip: You can refit the bezel, leaving the plug exposed, but make sure you tie it so that it can't drop back in the hole. When you get the new switch simply push the plug on and press the switch back in to the bezel.
I dismantled the dash and removed the switch and reassembled it. The securing clips at the base which are ridiculously thin had snapped which had allowed the switch to push too far through. Anyway I superglued the unit together as the broken clips wouldn't hold and reassembled the dash and it now works fine. I have also ordered a new switch from LR which I will fit in due course.
Thanks for the advice
ah, good ideas like that tend to over the heads of the P38 designers, after all there designs never go wrong, ever!dun know about the RR but some cars have a lever in the near the filler usually in the boot . that will open the flap if yer battery is flat of the button just dint work. might be worth a look , usually hidden behind some carpet