2011 Sierra OEM backup camera

[Slader442]

New poster here, but been a fan of the General for a long time.  Anyway, I installed a factory nav system in my 2011 sierra, and thought it would be a good idea to add a backup camera, also a gm part.  I have the camera and harness, I don't know where the harness is supposed to plug in once I get it to the cab.  All of the parts are gm parts, I have the numbers all written down.  I've gotten some deals on the stuff, but I'm in it for quite a bit of cash and I can't figure out my next step.  Any help would be appreciated.  Thanks!