I'm working on that now as I removed the rear seat, package tray, rear trim panels and the metal qarter window moulding. They are gettin a fresh spray of semi gloss black which they needed anyway.
I guess it's easier to leave the backseat & stuff in till the headliner & bows are installed since you can sit in the seats at first. That's the way I did it at least.
Lots of trimming to get the rear window & sail panel areas looking correct. The sides and front will be easy compared to the rear/side panel areas.