I think what he means is the whole shock is turning on the bushing mounts, which is causing the res line to hit <-- this portion being his concern.
Jack it up and remove the tire as stated above, then you will either need to brace the shock body with your hand (or someone elses... and use a glove), or use a rubber strap wrench (
Like this... Harbor Freight, Northern tool, etc sell them too) to hold the shock body. We use those on our race car's and bike's coilovers to adjust... they wont mar the thread surface, and work alright when we dont have another set of hands or a coil compressor. They break often, so buy a few... they're cheap!

If you cant get the strap around the body (coil too high), you can strap around the shock head, just be careful of the res line.