Can I beat this with a hammer (rear tire well)?

I would like the idea of a few relief cuts on that hump, then warm it while working it out, then weld up the cuts. Grind down to a finish.

I would think the relief cuts would lessen the chance of distortion. I'm thinking use a cutoff wheel and do a 2" cut leave 1" and so forth from one end of the hump to the other. It would be much less stress, if I'm thinking about it correctly.