Bolt turns but won't unscrew

Look behind the bracket on the strut. There should be a nut built into the bolt that you can use a wrench on to hold the bolt. If yours doesn't have that nut, use an impact wrench to "pulse" the nut off. Tap the trigger repeatedly and hold it for just a fraction of a second each time. Put some hand pressure on the link too. Each time it starts spinning it will shock the nut off a little. The same style is used on the front of Dodge Intrepids. I replaced gazillions of those. What worked real well was to grab the bolt right through the rubber boot with a curved jaw vice grip pliers. Let the impact run continuously until the boot starts to smoke, then tighten the pliers. Keep on tightening the pliers as the boot wears away. Eventually the shocks from the impact will convince the nut to walk off.

Those are the fast ways when you get paid by the job and time is money. The slow way is to use an air cutoff tool to cut the nuts in half and split them off.