If I remember correctly, there is a metal piece that a sticker goes onto. The sticker wraps around one side so as to have sticker material on both. That slides into place between metal, where two bolts hold the entire assembly together. BTW, you actually have to detach the support from the hatch. So do only one side at a time.

I wish I had pics to show you exactly what I mean. If you can provide pics of the pieces you have purchased, I can walk you through it.