One thing about the BFH is you can do stupid real fast with it.
Try a couple of Vise-Grip style pliers. Lock them down and start the folds, then BFH...the really cool kids with over size shoes like to fold them to the out-side, i hear more room.
I redid this mess with 3 vise-grip pliers, squeezed the seam flat then hammered inward, turned out pretty good considering i botched it the first hammer attack.
Tried the cut in 4" spaced sections on one side.
Then i just folded the other side thinking...less edges, less rust, less potential cracking do to cuts in sheet metal.
Also that seam goes up a way, behind the fender liners.
This guy...me...Whoops!