If you're talking about the channel at the bottom of the window glass that the regulator runs on, soak it in solvent (the shop manual says gasoline!) Its just a press fit with some glass setting tape with a little 10 weight oil to soften it a bit. You might be able to just tap the channel off, or if there's just glass shards left in the channel, dig them out with a screwdriver or other implement to reuse the channel.
