Set a  regular steel hex nut on top of the boogered screw, weld hex nut to screw.
remove your newly fashioned hex bolt with correct size socket wrench.

I use a wire feed MIG welder   for this type of broken screw removal,  often.

 

This. Impact-driver for the win.

AirArc...

And another vote for the impact driver. I would try the impact driver first, then if that fails try the weld-a-nut method if feasible. If you snap off an EZ out you're fucked.

Are you sure that it isn't staked or otherwise peened elsewhere?

Maybe a set screw or a pin?

I would soak it in Kroil over night.

Then if that didn't work, I would do the old farmer trick of setting it in Coca Cola, again, at least overnight.

Sometimes, all it takes is a really good downward smack to get it to free itself.

Then it will twist out like normal.

Is there an exploded parts diagram somewhere that has a parts list.

Wouldn't that be a kick in the nuts if the parts list showed it as having left hand threads?

After the Kroil, coke, and a good couple of smacks with a flat bladed screwdriver and hammer, I'd try heat first.  Maybe the tip of a sodering iron first in the slot, and then a MAPP gas torch.

And before it cools down, try the flatbladed screw driver smacks with a hammer.

Then I would try drilling it out.  Yeah it would be nice if you had left handed drill bits, and maybe left handed taps, and a drill press, with a cross slide vise.  Just don't fuck yourself any further by breaking a tap off in the hole.

That's what an impact driver is for. It twists the bit (blade, philips, allen, torx) slightly when you hit it with the hammer.  

Still have not gotten the screw out, been busy lately
but considering the amount of heat and force I have put on that screw I doubt it will come out

Here is my plan of attack,
dremel a new deep slot and use an impact screw driver
If that fails, try welding a nut on with a flux core welder
If the nut just breaks off I will try this

Thanks guys for all the suggestions... and as one guy said this is why arfcom is truly great

Ok, keep us posted.
Good Luck.
And, yes great people here for info, such as an obscure automobile problem I had long ago.
Was ready to give up, posted here, Ten Minutes, Problem Solved!

Remove the bolt and rear cover to gain access to the screw from the front. Hit that with a 50-50 mix of ATF and acetone. Let that soak in for a few minutes. While that is soaking in, cut a wider slot with the dremel. Hit the screw from the front with heat from a mapp-gas torch for 30 seconds or so, and use an impact driver to pull the screw. Repeat these steps, as necessary, and it'll come out.

OP, if you have a mig welder, select a nut that fits the outside diameter of the screw head, set it in place, then weld the nut to the screw head thru the center hole of the nut, let cool until the orange is gone and throw a socket on it and remove it....by far the easiest way to remove stuck bolts/screws..the heat of welding will expand the metal as well.........

Apply windex it will dissolve the anodizing. You could also maby use household ammonia applied carefully, tho I've never tried. People use windex to remove aluminum screws that have oxidized and bonded to the aluminum receiver they were put in.

 

That screw is steel. So is the receiver. You're saying they anodized steel?

 

Hell, I use a 90A Harbor Freight flux core for the same.

might as well throw it down a driveway at this point.

In since it started, did he get it out?
Less=More.

or use a nut buster. basically a rivet gun with a long leverage bar and use your tip of choice on the fastener.

Yep, best way to start IMO. If you do make a hole without the bolt spinning loose then put an easy out in there right away while it's warm. If that fails drill and tap to the proper size.

It's not that hard.