how do I bend a file shank?

Have you considered bashing it with a mallet?

-- My terrible signature...

I think you are already on the right track.
Heat it up and use a hammer/anvil…...
Hitting without heating it up first will likely just break it.

-- I'll be a woodworker when I grow up. HHHOPKS

heating the file up may aneal the metal and the file itself loose hardness

If its the file with the bend in the shank already then its been work hardened and you will likely not get it bent back or bent any further without heat

Heating that file enough to bend it will soften/anneal it markedly unless you want to retemper it. I see sets of those curved riffler files all the time for cheap. Would those work for you?

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

http://losangeles.craigslist.org/sfv/tls/3482962192.html

I’m not too far from Tujunga Loren.
If those work for ya PM me.

Good call gfadvm

File shanks aren’t tempered like the rest of the file. Just heat it red hot and bend it. As long as the heat doesn’t go any further down the file, it won’t hurt the temper.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened