Installing a Reversing System - DIY?

[gerger]

I have just received a gift of a reversing kit (NIKKAI) - 4 sensors and a camera - and a reversing mirror that shows the camera picture and also the sensor status, when the car is in reverse. The mirror claims to replace the existing mirror but I am not considering that. The existing mirror seems to be 'welded' to the wind screen. I would place the new mirror on the dashboard at the side.

I have a 6 month old Toyota Corolla Verso, so don't want to mess it up
It's my first Toyota - had a Spacewagon for 12 years.

Now to the question. Is this a DIY job? I am a competent DIY person and know the electrics well. However I have no knowledge of how to get the wiring from the rear of the car up to the dashboard. I hope there are snap in/out plastic parts to give access to wiring run? Or maybe the wires can be run externally on the underbody? The kit contains a die for drilling the rear bumper to mount the sensors and camera, so that should not be a problem.

So, is this something you would recommend I try? Are there any sources of information on access to the interior wire ducts. Or should I admit defeat and employ a pro?

Thank you

Ger