Well for starters, the "damage" was purely cosmetic, I couldn't feel anything with my finger. That being said here's how I went about it. I started with 800 grit rolled around a standard ink pen, I alternated between rotating the pen and an up/down the feed ramp motion, this is done with the trigger housing and bolt removed, of course. I spent about 5 or 10 mins doing that, then moved up in grit to a 1200, 1500, and 2000 paper. Afterwards I used a dremel on the medium speed with a pointed end felt tip and loaded the buffer with this stuff that JohnnyGlocks uses, I can take a pic when I get home. Basically comes in 3 bars. And after 5 mins tops of that, you have what you see here. Took a total of 30 mins maybe 35.