You might be able to squeeze the run channel felt passed the window with it still in the channel.... but it is easy to move the window out of the channel. You do not have to remove the window entirely from the door. All you will need to do is unbolt the center support bar that guides the window. It has one nut on the bottom center of the door & one nut behind the door panel top center of the door. With that bar loosened you will be able to move the glass forward and backward enough to remove/install the channel felt. When done, tighten the center support bar back up, align it to the original placement where the nuts marred the paint.