The seal is attached with two screws to the internal mechanism from the bottom. It is difficult to see the screw holes, so you will need to feel for the holes. Use a right angle drill or a right angle bit attachment to a drill or impact gun, or use a short screw driver. The panel will need to be pushed out so you can work on the bottom of the panel. Do not push the panel more than 18" from the centerline of the track.