Duster Headliner install

Hey guys, I have a 72 duster and I'm looking to install the one piece ABS headliner from year one into my duster. I got the car without one and I have zero idea on how this thing goes in. Where does it attach? I'm at a loss and its holding the car up to complete the interior install.

In my Dart Sport, there is a metal trim piece above each door/quarter window, then the visors, rear view mirror, coat hooks, dome light, sail panels, A pillar trim etc all hold it in place.