What's the best way to go about changing the rear window motor

Nick Drew here is the window control system manual Power Window Control System. It’ll tell you what and where to check. Next is the manual about the back door components showing you how to get into your door Back Door Component. My guess it is either the relay or the motor. check the power first and see what you come up with. Here are some instructions for the relay, and here is what your tailgate looks like being disassembled and here is a bit of a walk-through about the rear window repair. This video shows you about the motor. Not a great quality but all of this combined should get you there. Hope this helps, good luck.