I did. It wasn't difficult at all. I also did my fiance's Christmas gift of an M&P .45. So I have learned myself 2 ways to do it:
The M&P 9 you're looking at was done with a dremel sanding wheel to get the bulk off then fine tuned with files and fine grit sandpaper.
For her .45, I used a cut off wheel, then shaped it with files and fine grit sandpaper.
Either method will work well as long as you measure twice and cut once. Steady hand and DON'T RUSH! I'd post pics of hers, but its wrapped and waiting to go under the tree. If you have any questions or need guidance, PM me.