I think there is a metal channel that it clips into. Mine isn't looking the best. I thought about replacing but that piece isn't cheap. I am going to plasti-dip mine black.
it just pushes on over the pinch weld for the panel forward of the trunk.
you just push it off the pinch weld. the only problem is it's under the moldings on both sides of it. you have to lift one of the end moldings up and slide out the center molding forward.
just push it towards the front of the car.
partially open the top, grab on the lower edge of the molding and pull the molding foreword, some twisting action might help. you might have to pull and twist on the upper part of the molding also.
there are no screws or clips that hold this molding on. just tension from the molding and some soft strip calk sealing the ends.
here is a pic of the pinchweld area.
the center molding is installed starting in the middle of the foil tape. the edge where they join has a tin bead of sealer like strip calk to keep the water from leaking between the panels. this sealer helps hold the molding in place.
the slots allow the clips from the end molding to hold it on. these clips are difficult to remove without breaking something. there are barbs on both sides of the clip to help hold it in place.