I do not know if I would suggest taking off the hatch. unless you want the extra work. there are a few ways to do this surgery. First get new rubber for glass. Either use a sharp knife or chisel. I have used a chisel and just worked off the rubber. With the hatch on you do not have to worry about it moving around. It is also easier to lift it open and work on the other side if need be. Mainly work on the outer section, so you do not ruin your defrost.