How old is the seal? If it is the origional,your best bet is to cut the window out and buy new. As for removing the glass from a new seal, I have never attemped it but, I would believe it would be a difficult task for a novice to do without breaking the glass. I cut my windows out and had a professional reinstall them with new gaskets. He only charged me $120 to install both front and rear windows on my duster. Very cheap considering the cost of a new window.......