I need to remove a couple of (internal) doors in a flat in order
to take a bit off the bottom to clear a newly fitted carpet. The doors
have door closers fitted - the type with a "bicycle type" chain
running between and through two plates, one in the door and one
in the frame on the hinge side. Last time I did this I had a real struggle
getting the closer plates back in position against the pull of the spring.

Any advice on the best way of tackling this?

Thanks, David.