I am trying replace the liner, but don't know how it is attached to the astroroof? I pull down on the liner from the sides, but somewhere in the center it is still attached to the roof. I think I found one post saying something about the metal ring on the inside lip, am I suppose to pull on this? I got the outside edge plastic clips removed already. I see someone had put what looks like duct tape on the rear center of this piece of metal, is the metal split there, for easy removal of this trim piece?