I clamped the slider frame to the winshield bow to ensure the slider plexi would be tending to hold the bows in exactly the right place. I then carefully clamped the slider plexi from the front and back and drilled alternate holes side to side, starting on the front bow and then the rear.
White electrical tape on the bows was a great help to identify the contact tangent point for drilling. Later the front end will be drilled to 3/16" and the front bow drilled to 2.7mm for a 6-32 tap.
*** In retrospect, it would have been a good idea to clamp the lower edge of the plexi at the same time. While the photos show it, the instructions don't say much about clamping that edge - it's critical, so I'll have to use a die to offset the front bow holes further back as they're opened out to 3/16" later on !!
