That's what I had to do with mine. The tail pan was good except for one easily repairable pinhole. I cut all the spot welds, melted the lead out of the pan to dogleg joints and separated those. Then I went back to together in this order: trunk floor, tailpan brace, the tailpan and doglegs. I used sheet metal screws to hold everything together where the spot welds once were, and didn't do any of that welding until everything was in place. Then I started welding by removing a few widely separated screws at a time, then coming back and welding halfway between the first welds, etc.