Just completed the right side install (will finish another day--playoff hockey coming on before I'd finish the other side). I was confused on a few parts so I wanted to add my two cents for any others that might be too.
First of all, this is what the final product looks like, before you start reassembling everything. I was never really sure from the OP what section you were supposed to trim and where the new hole needed to go. The red line is approximately the section I cut off. The blue square is the second hole you need to drill.
A few notes on the trimming: my tin snips were crap. I bought "aviation" ones at Harbor Freight because they were a bit more robust, but I might have been better off with the cheaper smaller ones, or maybe should have gone to even bigger heavy duty ones. I ended up using a file to help smooth some of the more jagged edges and also create just a bit more space between the shield and the bracket in case there was any vibration/noise.
Also, the second hole you drill is right against a ridge. This doesn't allow the washer on the screw to sit flush. I used a light hammer to just flatten that section a smidge and then let the screw/washer do the rest when tightening.
The other part I wasn't sure of was the very beginning, because the OP just starts off after removing the rotor. I used this thread to get me to that point:
http://www.1addicts.com/forums/showthread.php?t=212459
If you have a wheel hanger pin, you can leave this in for the entire removal/re-install. It was very handy as a handle to keep the rotor from spinning when removing the screw that holds it in place (you can't use the brake because the caliper is off...).
Lastly, the only real snag I hit was getting the caliper back on. The pads may not have enough room to fit over the rotor, so I ended up spreading the brake pads with my fingers, and then just fit it back over the rotor starting at the top and then pivoting it into place. Then just bolt the caliper back in place.
Anyway, hoping to do the other side in the next few days. A test drive with windows down and no vents or radio going also reassured me that the new shields do not generate any sort of added wind noise that I could hear.