I used blue painters tape, a card board pattern to draw the line, and a new fine tooth blade in the jig saw. Did both my vetter and Honda windscreen right on the bike. After cutting, a few strokes with a fine tooth file to give a factory-finished edge, easy peasy. Brought them down to eyeline so I could see over the top. Note: On the Honda windscreen, the painters tape took off a very thin film that was on the surface. you have to stand at just the right angle to see it. Not a problem when riding. On the Vetter-faired bike I now get a slight push on the back of my helmet from the new wind pattern(turbulence) that makes my neck tired after a 3 hour ride. Going to investigate wind-wings to see if I can change the turbulence pattern. My neck got sore enough to finish the ride holding my head up with my hand on my chin!