This same piece of weatherstripping will fit your coupe, hatch and convertible Fox Body Mustang.
Start by pulling the weather stripping off the pinch weld.
Continue to work the weather stripping along the pinch weld till you remove it all.
With the old weatherstrip removed put it to the side.
Start at the original seem point make sure the leading edge of the weatherstrip is facing out, firmly press it down on the pinch weld.
Work the weatherstripping all the way around till you reach your original starting point.
Like the door to body you will have to trim it to fit properly.