Why don't the reverse lights work on my Nissan Micra?

Hi there

Can someone please help. My reverse lights don't work on my YR2000 Nissan Micra SE+. The bulbs are fine as I have checked them in different sockets, but I have seen elsewhere that it may be the switch on my gearbox.

1. Where in the engine compartment is the gearbox and what does it look like?
2. Where is the switch on the gearbox and what does it look like?

Any assistance would be greatly appreciated. Photos and full descriptions would be appreciated as I not much good with cars, but I really want to suss this myself without forking out a load of money.

Thank you :)