Nissan Micra K11 - Reverse Light Switch in Gear Box - hlines

Hi,

My reverse light is broken on my nissan micra K11, I know the bulb and everything there is fine so it leads me to believe the switch is broken in the gear box.

can someone please tell me how to get at that and fix it? I know it isnt required for my MOT but I'd like to have it working anyway :)

Cheers

Hannah