It helps if you use something like this air hammer with a chissle bit to seperate the panels.
Here I'm melting the lead out of the factory seam at the lower to quarter to rocker area.
Tail light pans got the same drill and split treatment where the quarters wrap around
same with inner wheel house to trunk floor...
A test fit for inspiration...
Note the extreme titty twister evidence...
Cutting wheel on the grinder way over penetrated, 2 shirts including my OD green chickenbuck shirt and the stone did it's final burn out on my... pectoral area.