In article ,
"MuddyFork" writes:
Can anyone advise on how I can remove the double glazing unit shown in these
pictures?
There seems to be a removeable white plastic bead on the outside, but it
doesn't seem to want to come out when force is applied with a paint scraper
as shown.

What you're doing looks correct.
You have to push it towards the glass by about 1/2mm before it will
disengage from a groove in the frame and come out. Use pressure to
compress the rubber seal and the foam seal to get the 1/2mm play.
Might want to wear leather gloves too, just in case you break the
glass or stab yourself with the scraper.

There's a black rubber seal between the beading and the glass on the
outside.

That's fixed to the beading.

There's also a black foam seam between the fixed inside frame and the
glass - it's not clear whether it is self-adhesive, or just pushed into
place. I've bought a reel of sticky foam glazing tape just in case.

It will be glazing tape - double-sided sticky. Stops the glass
being removed from the outside, and used for about 10 years now.

Do I need to cut out either the rubber seal

No.

or the foam seal

Yes.

before the beading can be removed?

No, you cut through it after removing the beading.
I suspect if you start mangling it before removing the
beading, the resulting extra thickness would make removing
the beading much harder.

Should I remove the vertical or horizontal beading first?

Depends how the corners are mitred. If they're clean 45 degree
cuts, it doesn't matter. I would do top last, so there's
something holding the glass until last moment. Sometimes,
they're profiled so one piece fits over the other. When I've
seen this, the verticals are over the horizontals so verticals
have to be removed first, but I don't know if this is universal.

You'll need someone outside preventing the glass falling
outwards after you've removed the beading, and you're on the
inside working on the glazing tape. I've seen it suggested to
poke a cheese wire through the foam from inside to outside,
and then the inside and outside person each grip one end, and
pull it round the unit. This may well bugger up the seal around
the glass edge, if you are planning on reusing it.

You'll then need to clean the remains of the glazing tape off
the frame, and the glass if reusing it.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]