Join Date: Aug 2009
Location: Washington, the state
If one of the mushroom heads, saw a slot across it for a big screwdriver. An impact driver might be needed. I think I had an EZ Out (bolt extractor) work once in 30 years. I've had some break off in the hole, more just ream the hole out, and I quit using them long ago.
For next time, take a look at your hex bits (Allen wrenches). If any of the ends are rounded, even a little, either toss and replace them or grind the rounded part off (shorten the wrench) with very frequent cooling in water so the heat of grinding doesn't take the hardness out of the tool. Always get the wrench all the way down into the hex hole, always hold it straight, and if too tight, don't just keep twisting until the hole is rounded.
"Older people who are reasonable, good-tempered, and gracious will bear aging well. Those who are mean-spirited and irritable will be unhappy at every period of their lives.
"Let each of use properly whatever strengths he has and strive to use them well. If he does this, he will never find himself lacking."
Marcus Tullius Cicero