I used an small exacto knife on the front notch of the frame to help finish it out. My Dremel didn’t reach and files were a pain and got gummed up quick. I also went as far as working my way up to 2000 grit sandpaper with a little oil and smoothed the areas the slide comes in contact with in the frame. Patience is key. They’re stupid easy to mil out but after you’ve gone at it with the Dremel, sanding and filing can take a little time to get it perfect so you don’t have any issues when firing. Lots of videos on YouTube if you get stuck!