Suburban tailgate removal

[Ipaintgrt]

I have an 87 suburban that I'm using for parts. I would like to remove the tailgate after removing the engine and part of the wiring. I want the rear window mechanism for a rear window project on my 68 GMC.

My question is does anyone know how to remove this with no power? It appears the window needs to come down so the tailgate can open. does anyone know how to get the window down and the tailgate open without power? or what color the wires are that need power to get it down?