When you get to the end of the header rail you have to make a hole in the fabric to clear the top post on the windscreen frame. Lift the header rail off of the windscreen, pull the fabric taught over the post, and cut the hole in the fabric to match the position of the post. Then put the fabric down on the top of the windscreen, replace the header rail on the post, and continue positioning and stapling the fabric on the front of the header rail as shown on the prior page.