Slide-out the slider, then use a plastic scraper to remove the old slider gasket. Then remove the adhesive remnants on the contact point using an adhesive remover solution or any other alcoholic solution, provided that it does not remove the paint. If the new seal requires you to use adhesive, apply the adhesive on one side, then apply it to the next one after installing the seal on the side with glue. If the new seal is push-on, it does not require adhesive to install. You have to push it into the pinch weld using a plastic seal. However, you should apply adhesive on the outer edges and corners to prevent moisture and air from leaking into the pinch weld.