To me, this was one of the more frustrating restoration projects for the door area itself. The metal clip seemed a lighter gauge material that bent very easily, and for me would not retain a shape. The second kit went a little easier for the metal part, and the rubber bumpers needed alot of trimming to fit. Dawn dish soap made the insert better,, again on the second kit.
My advice would be to have a kit to practice with, and a second once you feel comfortable with it. Just my take on the door bumper install. kb