Measure the height and width of the inside of the window frame.
Cut the tube of the roller shade 1/2 inch shorter than the width of the inside of the window frame following the instructions in the kit. A box cutter is required for cutting the tube in some kits; other kits have a tube with a perforation that can be torn by hand. Insert the hardware in the end of the tube.
Cut the vinyl 1/2 inch narrower than the width of the window frame and 2 1/2 inches longer. Tape the shade to the tube with duct tape.
Make a 1 1/2-inch fold on the back side of the other end of the shade. Hold the fold in place with double-stick tape to make a casing for the bar at the bottom of the shade. Use shears to cut the bar the same width as the shade and slip it into the casing. Roll up the shade before you hang it.