Rear interior window trim

Hello,
I purchased some rear window interior trim for my 69 charger.
The L shaped top sides, and the bottom straight pieces push onto the metal where the vinyl/cloth are pushed on and attached.
The bottom corner L pieces have no clips or attachment points.
Am I suppossed to glue, double sided tape, bubble gum these over and onto the straight and other L pieces ?
I dont see how they can go under these pieces to stay in place ?
Thanks in advance

They go over the side and bottom pieces and are held in place with screws-two per corner piece.

Thank you