In article ,
Robin wrote:
Yes. If you can, drill the pilot holes for the fixing screws right through
the door keeping the drill absolutely square.

The OP reported 2 problems. What I posted was addressed at the second -
viz. getting the screws in straight. I don't see why that requires
pilot holes drilled "right through the door". Nor do I see why the
drill has to be "absolutely square". But then all I was after was
something better than can be done when there's a big knob in the way.

Because it is often slight misalignment that causes the handles to stick.
It adds friction to the system.

--
*Being healthy is merely the slowest possible rate at which one can die.

Dave Plowman London SW
To e-mail, change noise into sound.