If you are patient, you can pull old ones with thin piano wire or similar to cut the factory dow 795 glazing. The documentation archives have the instructions from hunter. Better to have new ones made using old ones as templates... about $120 per at a plastic shop. New ones are nice and shiny. You may end up with stress cracks that don't seem to be immediately apparent if you try to pry too much with a putty knife trying to remove and reuse the old ones. Use the dow 795 to rebed. Did mine last year and its nice to not to have stained cabinets and wet cushions...