Hey Barry, I tried to find how to cut it, I can remember someone mentioned it a while back. I want to say bolt cutters, fast and easy IMO. Then I read that people just use tubing along the sides to hold it in place. Something like 3/4" hose with a cut along one side, lengthwise and it will fit along the edge well.
Do you already have some? Why are you using it if you dont mind me asking?
Eddie