Removing floor pan and quarter panels advise
No, You don't need to remove the roof. Cut out the spot welds between the roof and quarter panel, then all of the spot welds around the perimeter of the quarter.
The quarter panel is installed behind the roof at this seam. (See pic) This is the hard part, removing the quarter from under the roof.
I found it helps to cut the spot welds part way up on the back window/roof (See pic) so that you can spread the roof out some to help get the quarter panel out. This also helps installing the quarter on the other car. If you're not saving the roof of the donor car, you can cut the roof just above the seam where it meets the quarter panel.
You'll have to wiggle the quarter panel around some to get it off and I found it better having a helper.
Quarter panel is under roof at this seam.
Cut spot welds part way up rear window to aid spreading the roof away
No, You don't need to remove the roof. Cut out the spot welds between the roof and quarter panel, then all of the spot welds around the perimeter of the quarter.
The quarter panel is installed behind the roof at this seam. (See pic) This is the hard part, removing the quarter from under the roof.
I found it helps to cut the spot welds part way up on the back window/roof (See pic) so that you can spread the roof out some to help get the quarter panel out. This also helps installing the quarter on the other car. If you're not saving the roof of the donor car, you can cut the roof just above the seam where it meets the quarter panel.
You'll have to wiggle the quarter panel around some to get it off and I found it better having a helper.
Quarter panel is under roof at this seam.
Cut spot welds part way up rear window to aid spreading the roof away