Bolt Head Rounded - How do I get it out?

Today I was trying to change the front brakes on a 2002 Ford Ranger pickup truck. One of the bolts that holds the metal frame which holds the brake pads had a rusted bolt. Penatrating oil didn't help and now a 6-point socket won't turn it without slipping off because the bolt head has rounded off. What can I do to get this bolt off? The bolt is in a part of the suspension where I can’t use anything but a socket. :banghead:

I was at Napa getting a drain plug for a transmission. They sell a set of Irwin extractors Sears also sells them. You tap them on and use a ratchet to remove the bolt. They look they have spiral threads on the inside.
I have used a 9/16 socket for a stripped 15mm tapped it on with a hammer and pulled a few bolts. use a 1/2 for a 13mm. I've done this for years on corroded exhaust manifold bolts. Before starting tap the bolt good with a hammer to try and loosen any rust. If they used loctite try heating up the area where the threads are about 350 degrees to allow the loctite to go back to a liquid.
I've done this for years on GM u-joints as they were next to impossible to remove without doing this. It also helps on bell housing bolts with Torx Plus bolts Napa also sells torx plus and sears sells S-K Torx Plus. You will eventually need a set. Also on ebay.

If your talking about the caliper you can turn the wheel to get better access and get a big pair of channelocks on them. Other people swear by vise grips but they usually make them worse unless you don't have the hand strength to keep the channelocks closed.

If your talking about the caliper you can turn the wheel to get better access and get a big pair of channelocks on them. Other people swear by vise grips but they usually make them worse unless you don't have the hand strength to keep the channelocks closed.
Use the real Chan-Nel-Locks too! Those cheap ones, including the Stanleys, don't work at all (trust me, I know! :mad: ). Ideal would be another brand to try. The good ones will grip when you just push on the top handle. The cheap ones slip off no matter what. Busted my knuckles quite a few times with these things. I prefer Vice Grips myself by getting them as tight as I possibly can and still be able to get it to lock.

the caliper mount normally has lock tight on the bolts, its gunna be a bitch to get them out now. what you can do is take a socket (impact socket or high end crome, no chinese)1 size smaller or try a standerd size socket , pound it on the bolt, with a hammer, then try and take it off with a braker bar or large wrachet. bolt extractors are kind of the same theory(pound it on)