76 Dart Sport Headliner Install????

my car came without headliner.
What exactly hold it up? clips, windshield gaskets,etc..?'
i'm not sure?
i bought one from Dante's
then later bought material.
should i spray glue? if so how do you get the corners correct?
with the material?

The originals are a sort of cardboard/pressboard, which, when folded properly would be held up along the edges by the interior molding trim, and by the dome light, and tucked under the windshield gaskets at the front and rear. That's how my 75 is, and my 73 was...