In article , Bill
writes

Angle grinder..........

Seriously an angle grinder with the guard removed and a thin disc, maybe
a shade suicidal but it works well. I removed a window rack bolt this
way only a few weeks ago. If you have 3mm gap you should be able to get
the disc in without damaging the door or frame.

I'm sure some one will come up with less dramatic methods though.

A slightly more sedate method would be to remove the hinge pins if you
can and lift the door out that way,


All good stuff but I don't think there is any reason to remove the
guard, it should rotate when loosened and there should be plenty of
depth with a new 115mm disc.

A thin (1.6mm) disc will certainly make it less of a drama, more
clearance and less metal to cut out. Treat the striker plate as
sacrificial and cut close to it, you'll get a free replacement with the
new lock. If the bolt has (internal) hardened rollers, just keep going,
they'll give in eventually.

IME, the hinge pins are usually masked by the cut into the door but the
o/p may be lucky.
--
fred
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