I used a flat 6" fine file. I needed to file a bit of material off of the lug at the bottom of the slide, and a bit off of theguides at the front of the slide. I used the file two strokes and check technique, which takes longer but eliminates over removal. I'd like to hear how yours comes out. I was at the range yesterday witha guy who has shot a lot in the past. He was very interested in my 75 BD with the conversion. He has arthritus in his wrist and can't stand the recoil of even a 9mm. He liked the .22. He was showing me that the gun can shoot 6" groups at 50 yds shooting one handed! He used to be on a marksman team. I'm not there yet. The price of that expertise may be the arthritus in the wrist.