Old thread but I found this thread and forum while trying to figure out how to solve the same dilemma as the OP.
Thought I would post my solution in case anyone else needs some ideas in the future for the same problem.
03 Limited, 4wd, 4.7L.
183k miles, was a PA car for most of its life. I bought it in OH at around 120k, now in Raleigh NC.
Rear shock mount sleeves on both sides were rusted/seized to the mount.
Tried to pry and beat them off, no luck.
Used a jaw puller to pull them off, but just tore the rubber bushing off and left the sleeve still seized to the mount.
Tried for quite a while to beat it, rotary hammer drill w/chisel to the tiny crevice at the back of the sleeve, Kroil, heat, more beating, jammed an impact socket on it (didn’t have an extractor socket that big) and hit it with an impact gun hoping it would break loose.
Would budge a bit.
Finally broke out the grinder.
Started at the top and started slowly shaving it off. Didn’t cut straight in as I didn’t want to cut into mount.
Once you have ground through the sleeve you can see a line differentiating the metal sleeve from the mount.
You can use the line as a guide as you work your way around shaving/grinding the metal sleeve and not shaving off the mount.
Shaved down on both sides from the top until most of the top half of the sleeve was gone.
At that point I was able to tap the edge of the remaining bottom half of the sleeve and it fell off.
Probably took me around 15 minutes of grinding to get it free.
Hit it real good with a wire brush on a drill to ensure all rust was removed and slathered the mount and inner sleeve of the new shock (and of course the bolt, but it didn’t give me any issues) in anti-seize before installing.