Snap-on makes a great tool and you don't even have to take out the radiator. The extractors come in a set, and I think there are about 8 different sizes in the set. They are about 30mm or so long and have a left hand scribe on the top. You just get the right one, clean the head of the bolt and use a long box wrench with a pipe to crack it loose.
If you take out the radiator, you will also have to take out the A.C condensor.
You don't want to do that!!!