On Thu, 15 Jul 2010 13:55:13 -0500, Wilfred Xavier Pickles
wrote:

If there are rubber spacers around the
sash unit, they may be flattened, some, at the bottom and they are
likely stuck down, also. Try running a thin knife blade around the
edges... see if you can feel something that would be contributing to
the "stuckness".

Mostly it won't penetrate at all. Around the bottom, it will go
thru half-way (only) in places.

I have a "cake spatula" that I use to de-glaze glass.*

Use good gloves, working the tool between the glass and frame. Work
around the frame / glass. The idea is to separate the glass from the
frame. The spatula is flexible making it easy to work with.

Mine is 1 inch wide and 12 inches long -- looks like the middle one in
this pic:

http://selfservebaker.com/decorating...es/spatula.jpg