This is an easy-out. It will either be your best friend or your worse enemy, but that depends on you.
First drill a hole in the center of your bolt using a drill bit about the same size as the end of your easy-out. I don't know how big your bolt is, but your easy-out size at the business end will need to be a good bit smaller, but not tiny by comparison. The hole needs to be deep enough that the sides of the easy-out meet the edge of the hole, and then a little bit further. The easy-out will bite in, and you don't want it to bottom out in the hole.
One you have a good hole, gently give the easy-out a couple of taps into the hole. Using either a tap handle (preferred) or a vice grip (less preferred, but usually what's handy) carefully twist the bolt back out of the hole. You WILL need to replace the bolt, but if its stripped you should do that anyway. An auto parts store might be able to help you, or possibly order it from someplace like rockauto.com
I hope this helps!