Anyone trim the ends of a Profile Design HC Mount?

What did you use to trim it down? Mine extends about 3/4 inch on both sides of my extensions, and I’d like to make it flush. What works?

My bars are narrow. For the Profile Mount I used a hacksaw to trim the excess & a flat needle file to smooth the edges:

http://i53.tinypic.com/71ika0.jpg
http://i51.tinypic.com/jqqet3.jpg