Put it in (insert the rods and hang it in the car), pull it slightly toward the front and glue the front down. Go to the back and pul it tight and glue it down at the back (about 3/4 way across the window opening). Starting in the middle on each side, work toward the back or front; attaching the sides down as you go - pull it tight so as to pull as many dimples and puckers out as you go. That should work well. If there are any "shipping wrinkles", they will come out over the next week or so.

You can view this online instruction guide for a 56 Belair and get a rough idea of how to install the bowstyle headliners.