Was able to save the center brace.
I used a 1/8 inch drill bit and drilled a pilot hole in the center of all of the spot welds. Then a 1/2 inch rotabroach sheetmetal hole cutter and attempted to just go though the upper skin. When using the rotabroach cutter, the chips were clean and then you can feel the cutter when it goes through and starts to touch the frame rail. You will sometimes see a puff of dirt or rust powder when it breaks though. The cutter will last longer if you spray a little wd40 or cutting oil on the cutter every other hole or so. The pilot hole will be welded up later when you replace the pan.
I hope this helps anyone thinking about this project.