I removed mine when it stuck in the open position the front bolt came out easy the back bolt right up to last thread as I wasn't aware the damper was pressing on the bolt.
My local dealers mechanic told me what I was not doing when I tried replacing it the second hole was blocked by the damper.
To save removal his everyday solution was to get a panel pin hammer [thin handle] a fairly thick pad of material/rag.
Have the bolts and new tow hitch ready, a screwdriver that will fit the hole. Put the handle of the pin hammer in the tube and the pad over the hammer head and place against your stomach and push hard it will eventually move the damper back so you can slip the screwdriver in the bolt hole to take a breather. Push again pulling the s.driver out and push the bolt in fully home follow up with the second bolt.
You might but I've not tried it. be able to clamp mole grips to the damper rod to act as a stop holding the damper behind the bolt but you might need to hitch up and reverse with chocs under backwheels this should push the damper back away from the bolt while someone is applying the mole grips to the rod to act as a stop.Then you won't have to strain hard with stomach to push the damper back,
charlie
April 2009