I attached mine with aluminum pop rivets:
1.Temporarily tape new panel to door in the position you want it.
2.Hammer "prongs" on metal top flat, and set on door overlapping new panel.
3.Mark panel where metal top ends, remove both pieces.
4.Clamp top to panel on both ends, drill hole for rivets, I used the shortest 1/4" rivets I could find and used a washer on the inside of the panel to keep from pulling out. I mounted mine with the head of the rivet to the covered by the foam and vinyl.
5.Use a good spray adhesive to install first the foam and then the vinyl over the metal top.
6.Install the weatherstrip (window fuzzy) the same way with rivets.
That is the way I did mine 8 years ago and they still are together.
Jim H
69 Malibu