Help With Rocker Bolt

Help Help Help!!!!

I killed my 408 and had to settle for dropping in a bone stock 351 so i can still get to work while i rebuild the 408.
Now here is my problem, I have never ran into anything like this and I hope some on you have and can help me with it.

The bolt in the exhaust rocker of the #7 cylinder broke off in the head so the bottom half is still down in there, any way to fix this without removing the head? or just tell me the best way you know of to fix this i have to get it repaired asap cuz the wife isnt too cosher with me driving her 2003 so much.

yea, i believe it was over-tightened, my torque wrench took a dump when i had 4 rocker bolts remaining, so i guesstamated the torque of these, and this just happens to be one of them, and this happened after only 50 miles on the engine, so im pretty sure it was over-tightened and as soon as the bolt got heated up it became weak and broke off. I delivered the car to a machine shop today and they will have it ready tomm. for me to pick up. gonna cost $150.00 for the labor tho, i guess i should have just spent $50.00 on a new wrench and took the safe way out, but you learn from your mistakes, , , , ,ya' know.

it was a kinda radical motor, 647BHP, I let it set up while i was out of the state for over a year, and then the first thing i did was get in it and drive it just as hard as i could without doing any maint. or anything else for that matter.

i got back to Georgia from Florida, and immediately fired up my ole' stang and tried to drive it as i always had, it developed a slight skip and then #1 cylinder went out totally, when i pulled the plugs i could see it was the #1 so i pulled the head and the rings were shot, and i had driven it enough trying to get it back home that it now needs to be bored again so much for the 408 but maybe a 418?