I used a piece of masking tape to mark all of the holes that attach the rear window to the top skin. I laid out the masking tape 5/16″ from the edge of the skin (half of the 5/8″ overlap between the window and the skin). I marked the start and end points on the tape, then laid the tape out straight to lay out the holes. I then put the tape back on to transfer the holes to the skin.
Here’s a closeup of the transferred holes. Afterward, I punched the skins and drilled these out with a #50 drill. I drilled these small so they would act as a pilot for the plexi bit.
I also trimmed off a bit off the base at the forward end of the rear window to clear the cabin frame attach angles. Without this, the window can not be pulled fully down against the cabin frame.
Finally, I reinstalled the window in preparation for drilling.
