did the exact same thing! that's hardened steel so you can't redrill it. Someone said to weld a piece of metal on there and take some pliers and try to unscrew it again. That's all I can think of, I never gave it a try. The bolt is still stuck
You can weld a bolt to it, BUT chances are the weld will cover the outside, I had to do that for a locking lugnut that was on my wheel when I bought the jeep to get the lug off... But there was more room to weld around it....
I'm sure you saw on the bolts that did come out, they're coated with loc-tite. Try heating it up some to break that bond. Also, drag a razor knife around the head to break the paint bond, every little bit helps.
To remove a broken drill bit depends what it is made of
broken HSS bit can be drilled with carbide bit
Carbide bit can is brittle and careful use of punch and hammer can slowly shatter the broken off carbide drill bit tip for removal with a pick and suction
Neither is fun but both can be done
Best just to be more careful with removal in first place
A properly fitting bit carefully tapped all the way into the bolt head, plus a heat gun plus a small end wrench over the hex of the torx bit plus a hand impact driver (the kind you hit with a hammer) and if the torx bit itself starts to deform and show a spiral twist stop and get another hopefully better torx bit and don't use the weaker torx bits with hole in center for security screws
I had the same stuck/stripped windshield bolts when I tried to mount my windshield light brackets. I ended up welding a nut onto the bolt head. The nut allows you to heat up, and melt a good amount into the head of the torx bolt. I then just backed them out with a socket. A local shop could do it for you for a couple bucks... make sure you protect your paint!
__________________ 2002 Sport, for waves & woods,...and winter.
I'm going to recommend what was suggested up top about trying to tap the bit/bolt out...it sucks but will work just takes a while. I had to do something similar with my tailgate hinges. I decided to get an air impact for the windshield hinges and it still was tricky but works a lot better, although it was $50. Good luck!