Not seen any how toos on the reverse light switch but it just so happen to have an engine and gear box lying around....reverse light switch is circled
Youshouldbe able to get to it from the passenger side rear, jack up the rear or put on a ramp to get the height, the cable is connected higher up, if your agile you may be able to get it from below or through the boot
A couple of points: first, gearbox oil runs out when you remove the reversing switch, so be quick with the replacement or better, have a bung of some sort ready. Second - my replacement reversing switch did not work when I first fitted it. It tested OK though with a multimeter after I took it out again when I pressed the little plunger. It turned out I had to adjust the depth it was at with a washer. Can't remember the exact details of whether I needed a thicker or thinner washer, but if your new one doesn't work in situ so to speak it may just need a bit of tweaking.