I tried to find the site but couldn't. Anyhow, to gain access to the left rear area, the floor cover, the spare, and the lower cover on the cargo sill must be removed.After removing these, several bolts that hold the left rear panel need to be taken out with a socket and 9" extension (10mm I think). Most everything else is just clipped in place. I used "t" connectors to hook up the wire for the camera.
The wire for the camera in the tail light must be installed with the aid of a electrical fishing tape (found one at Harbor Freight for a good price)
and routed to the license plate area.
I hope this helps, it's been a while since I installed wire for additional back up lights (the same circuits needed).