Maybe you could give details of what the actual damage is , a flat area, a corner, the side? And whether he wants to maybe repair it in place or intends on removing it to repair. In place I would sand all the paint off around the hole, degrease, cut a patch out of thin steel or aluminum, run a bead of ultra black around the hole, fit the patch firmly, let it cure, then seal the edges of the patch with a wide seam of more ultra black. Trust me, it ain’t gonna leak or fail. Otherwise remove the pan and braze the hole or patch and braze. Brazing for most of us, welding done by someone qualified and you pay accordingly for that skill
