Spray some good penetrating fluid on the top mount nuts. Up through the wheel arch. Both of my front top mounts had 1 bolt that ripped the nut out of the mount. A right royal pain in the arris to sort. Do the front, then the rear. No need to have the whole car jacked up. Rears are easy enough to do. I'd look at new top mounts and if they go like mine it's the only option for you.