Canopy vinyl roof for Dusters/Darts Sports etc......

I have a '74 Duster and want to add a canopy style vinyl roof. I have collected all the trim that I need for this but my concern is getting the top pieces to fasten. I have the 2 small pieces for the bottom of the A-pillar, I have the drip rail pieces and I have the roof trim. What do I do to the roof to get the roof trim to attach? Thank you!