Headliner:
Get some "Binder clips" (The kind you use to hold a thick stack of paper) from a office supply store and some 3M spray adhesive.
Let the headliner sit in the sun for a bit to warm up and stretch out.
Place the metal bows into the headliner and install the front one. Clip the headliner to the front windshield lip. Work your way back using more clips at the door lip. Once you are satisfied that it is centered and will fit, go back to the front and remove the clips. Spray some adhesive, replace the clips, work your way back. Use a hair dryer for small wrinkles.
Windows:
Put the gasket on the glass.
Place some heavy twine or 14 - 16 ga wire in the gasket channel. Place the window on the car with the bottom of the gasket over the lip and while applying gentle pressure on the outside, pull on the twine to roll the gasket over the lip. It helps to have a helper, but I have done it alone.
Good luck