A sharp chisel works wonders for getting under that lip and peeling all the spot-welds!
Carefully form the new piece
Glue it into place
There's a nasty crumpled bit here that took a fair bit of effort to even look [i]this[/i] good.
But, it all looks a lot better under a heavy coat of primer. A little smear of filler will sort the rest of it out, and it's on the roof anyway so it's not the end of the world.
Next time, moving onto the other side of the roof! I've also got wires run in for door switches for the interior light, so that's going to be quite nice to get sorted. Still just chipping away at my priority list, which looks deceptively short. 