Are you wanting to retain your camera?
I've taken several of these tailgates off, on trucks I was working on (last week I did a '14 seirra Denali).
There are 2 wire loom clips on the rear body panel on the underside of the bed. You will need to drop the spare and or remove your license plate to get to them, and then you can pull the red switch out on the plug and then depress the button on the connector and remove from the connector pannel (on the drivers side on rear frame cross member)
The camera is in the tailgate handle/ bezzel assembly, and can be removed... but have yet to see one installed on a 5er gate.
MillerTime- Future Sabre Handler!!