If it's an LT77 - get underneath the car (with suitable safety precautions of course), feel up the back of the gearbox and when you get near the top, you should be able to find a pair of wires. These are attached to the switch. They're spade connectors so should just pull off. Then you need a spanner to unscrew the switch. It's a bit of a contortion to get to it, but it's not too bad.
