Adding OEM back-up camera

I want to install a OEM camera and LCD mirror into my 2012 Double Cab base model. It seems to have the wiring already in the tailgate, so I'm thinking it shouldn't be too hard, right? I've searched a few places and haven't been successful finding a write up where someone has done this, but I am tired of hooking up a trailer by myself and having to get out of the truck multiple times.

Does anyone know where I can find a tutorial on how to do this and the part numbers to go with it? I doubt I am the first guy to want to add this.

 

subbed...would like to do this on my 2011. Harness is already there, if I understand correctly, and all I need is a camera and mirror?