Is there a special tool required to install the AA45 concealed door closer. I was wondering how you open and fix the second face against the spring tension?
Yes, they come with a small metal retainer which holds the chain out while you fit it. You’ll need to attach the plate to the frame (or a spare bit of wood) then pull the chain out as far as it’ll come and slip in the retainer. Next detach the plate from the frame and fit the door closer into the door, then finally re-attach the plate to the frame and remove the retainer, so the spring can re-tension the chain.