I have bolt extractors similar to the Craftsman ones mine are Irwin Bolt Grip. Works fantastic.
After you get the bolts out definitely use a liberal application of anti-sieze on them going back in.
I just found out they make it in the handy gallon size pail and an aerosol can.
(You're going to get it everywhere anyhow might as well just spray a coat on and get it over with!)