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

Do I need to cut out either the rubber seal or the foam seal before the
beading can be removed?
Should I remove the vertical or horizontal beading first?

Thanks

http://i35.tinypic.com/256wtg4.jpg
http://i38.tinypic.com/23hr6gw.jpg
http://i33.tinypic.com/34euxd3.jpg