1. Cover the upper portion of the screen, or where you think you want to cut it, with painter's tape. Do a good job and make sure to overlap the rows of tape.
2. For the sides of the screen, measure from the windscreen brackets. I simply put a piece of tape against the W portion on my 2008 and it looked about what I was going for, a strip about an inch and a half wide. no matter how you measure for one side, do the EXACT SAME THING for the other side.
3. For the radius, I tied a piece of string to the BASE of a Sharpie marker. Then I took the other (the free end) end of the string and held it down near the nose of the bike, in between the headlights. I played with a few different radius shapes (radii?) to get the shape I wanted. To do this, simply hold the free end down tight and use the string as a giant compass to make your line. It's VERY IMPORTANT to tie the string to the BASE of the marker and hold it PERPENDICULAR to the screen the ENTIRE TIME YOU'RE TRACING YOUR LINE.
4. For cutting, put painter's tape on the shoe of your jig saw. This will keep it from scratching the screen as you cut. Or, you could cover the entire screen in tape.
5. To cut the screen, I used a 20 tpi blade and rand the saw on a medium high speed. Since you're trimming the screen, test the saw to see how it feels on the portion that you are cutting off before you actually get to your line. This will let you see what the saw feels like when it cutting through the screen. When you're ready, start on your line. Be sure to cut on one side of the line all the way through. What I mean is, if you choose to stay on the outer portion of the line, do so the entire length of the cut.
6. To sand the screen, USE A BLOCK with STRAIGHT SIDES. If you try to hold the sandpaper without it being tight against the block, you run the risk of the paper accidentally scratching the front or back of the screen. The area that you're sanding is very narrow, only about 1/4" or less. Take it slow. I started out with medium paper and progressed to very fine. Run your finger over the edge to check for irregularities where your cut might not have been perfect. Sand more on those areas.
7. When you have the edge nice and smooth, CAREFULLY AND LIGHTLY run the sandpaper over the "lip" of the screen to take the burr off and give it a smooth edge.
8. Carefully take a Sharpie marker and color the edge that you just sanded. Let it sit for a minute or so, then wipe away the excess ink with a clean paper towel. Repeat as often as you wish to get a dark edge. I did mine about 2-3 times before I was happy with it.
9. Reinstall and ride.
I hope this helps you, FJR Steve, and anyone else who is interested in trimming your stock or aftermarket screen. I actually trimmed a National Cycles V-Stream screen. It was WAY TOO BIG for me.
Any other questions, please feel free to ask.
MG