Cut appox 1 1/2" off of the top excess material where it goes along the back glass. Then peel the vinyl back off the backer board for 2-3 inches all the way around. Re-glue it with spray trim adhesive or contact cement. With plastic trim panel tool or putty knife you can pust the excess under the gasket. Also , hot glue gun the square on the back that holds the clip before you install. This has worked pretty well in the past.
Good luck