The damper is very cheap and easy to replace. You can actually remove the bottom bolt in-situ, the head of the bolt will squeeze by the flywheel - just. To replace it just put a big strong lever in the plastic block at the top of the spring, undo the bolt holding that block in place, then carefully lower the spring down (with your lever).

When you remove the damper, keep it. The new one will 'go' after a year or so, and its often just the bushing that 'goes'. You can push the good bushing out of your old damper and use that as a spare for the new one.

If I were you I'd replace the spring as well. Mine snapped at the hook a while after I replaced the shocker. Metal fatigue, and you can't drive without it.