I'm surprised people are using what I believe is petroleum based glues like MM cement. Get that on the clear window, and your window is trash.
I prefer 2 part epoxy. Should any excess epoxy squeeze out around the edges, just wait for it to reach a semi-cured state, then use a toothpick to gently roll it up like it was rubber cement.
Also try covering the open areas of your window with Post-It note, cut to shape. Both sides. If you get some glue on your finger, it's not the end of the world.
Greg, good tip on that .020 poly. Thanks.