removing it is pretty easy. What I used to do is lubricate the gasket next to the glass real good then work my way around it with a piece of stiff plastic like 1/4 in plexi glass until I got the lube worked in to the edge of the glass all around and then I got on my back under it in the car and used my legs to push it upwards . I took about 10 out this way from parts cars . Don't pry up on the edge of the glass ,use pressure from below and not too close to the edges. If you have a new gasket it's real easy if you cut around the edge outside but getting a new gasket could be tough.I'm assuming you want to re use the gasket