Mestorod70,
I eventually had to cut the quarter due to rust and found getting that quarter section out made it a whole lot easier putting the trunk pan in.
Below are a couple video's using a manual & pneumatic flange tool. I have a pneumatic one. I haven't started the work yet but after seeing the video it makes perfect sense. I do have to admit that I'm in no way a professional body man but... it does make sense. Perhaps if there are any body guys out there hopefully they could chime with their experience. The second video shows using the pneumatic flange tool.
https://www.youtube.com/watch?v=rpH50kh4W00
https://www.youtube.com/watch?v=1whkWuL8gRw
Perry