I haven't done it for this particular knife, but I have a few suggestions. If you have a drill, you can but small diameter sanding drums. Go for a high abrasion sanding grit, and run it at a medium/high speed, but go slow, put little pressure into it, and don't let the metal get even more then warm to the touch. Another option if you don't have a drill is to buy either a round or half round file and go at it buy hand, with the knife locked into a vise )or tied to a stake, fence, rail, etc. if you don't have a bench). Buy a drum or file smaller then the choil you want, and work in incrememnts.