I would very carefully cut off the damaged part and then serge the raw edge with a sewing machine. If you don't have access to a serger, or a sewing machine with a serging stitch, you can run a double or triple line of zig-zags along the raw edge. At least one of those lines of zig-zag should be fairly wide.

Turn up the hem about 1/2 an inch. You might be able to do 3/8ths of an inch, but much less than that is going to be tough and require a lot of patience. I'd then press the hem down, HARD with a steam iron, and pin it. Then I would hand-sew a blind stitch along the bottom, to hold the hem in, and then press again. I haven't used a machine-done blind stitch, so I can't comment to that, but hand-sewing a blind stitch along 20-something feet of hem will be 3-4 hours work. I don't know what the going rate is in your neighborhood, but I would expect to pay a tailor about $20 an hour for this, which means it would be about $60-$80 to hand-sew the hem.

The serging of the raw edge will be quicker, probably an hours work. All in all, I guess this modification will cost roughly $100 if you hire it out.

And then I 'd wear it.