Hi does anyone know the easiest way to get to the reverse light switch to replace it?

My Mazda 5 reverse light is intermittent, sometimes works, sometimes doesn't, sometimes stays permanently on.

I've purchased the switch from main dealer, now just preparing to change it. Can I get to it from under to bonnet? Or do I have to get under the car. Any advice or tips from someone who has done it already would be much appreciated

Thank you