So I managed to remove the quarter panel following the advice from Colin and Ben, it went very well :)
I took some dimensions and tried the quarter panel in, to see how far I need to cut the old one. It looks so good to have new metal on the car!

I cut the rear area, giving at least 10mm more, so I can refine the cut point later

Same on the B-post area

Then I grinded down the area where the panel folds into the B-post

And I separated from the B-post, getting it ready to remove the spot welds

With the help of a small screw driver I managed to locate the spot welds and drilled them out

I then cleaned up all the area with the wire brush

I masked the areas where I need to put zinc primer to weld in

And then painted with anti-rust paint


I removed the masking and aplied zinc primer


I still need to do some repairs in the central area, but for now this is all sorted and ready to receive the quarter panel
Next I gave it a go to the closing panel at the front of the wheel arch. I aligned it with the mounting panel and the boot floor


Then I tried the wheel arch on, to see how things were getting together. I still need to put the lip of the wheel arch on the other side...


I also tried the rear valance closing panel, unisng the rear subframe mounts


And finally I got the wheel arch in again to check aligment


Then I run out of time, but next week I will try the quarter panel and the wheel arch all at the same time to find the final aligment.
You all have a nice week.
Victor