I ended up buying two headliners as well. The first on I put in. Went pretty well until I got to the C pillars. Could not get that to work. nded up buying another and paying for installation.
You start in the rear on most of the A-Bodies and work your way forward stretching the wrinkles out as you go. There are two short wires that connect the rear bow to the window frame so when you pull it forward the bows stay still then when you get to the front, you stretch out the wrinkles along the front. The tricky part is around the dome lights, the more padding you have the easier it is to get the wrinkles out.