Sanded inside the fuselage with 60 grit sandpaper to remove sharp edges.
Cut out back windows. I used a Rotozip tool because I do not have an air compressor and die grinder. First I used the Zipmate right angle attachment and a dry diamond wheel for the relatively straight side cuts. Then I used a Rotozip bit to cut the corner curves. Finally I smoothed and finished the edges using Permagrit coarse and fine tool sets.
NOTE 19JAN2008: I finally decided that the Rotozip with 3.5" cutting wheel and no speed adjustment is a bit too big for this work, but that is what I used. If I was starting again I would get a variable speed tool with a smaller wheel.
NOTE: The method Arion uses to hold the windows in place while bonding has changed now that the windows are pre-formed rather than flat.
They no longer put the screws in the window itself. They use little tabs, where the screw goes through one end into the fuselage and the other sits over the window like a clamp. Then they fill the holes in the fuselage after the screws are removed.
I would think if you can avoid drilling the windows you should, due to risk of cracking.
