Cut the pitot tube doubler and laid out the rivet pattern. Center punched the holes and deburred them. I removed the center left upper skin to fit the doubler to the skin and installed the lower skin stiffeners. I stopped and scratched my head as the optional directions were Glastar not specific to the Sportsman. This is where Glastar saved the day once again. I found an old post on this manual update and printed the drawing. I measured outboard 4.5 inches from the outboard rib at station 69.0 drawing a center line to fit the doubler. After fitting the doubler and taping it in place I transfered the holes from the doubler to the lower center wing skin. I then removed the double to work on the pitot mast cutout next session.