Here's how I do it. Put the blade in a vise so it's securely held in a handy position. You need a fine file and some oil. Motor oil will work just fine. Dont grab the file on each end like one would normally file , but kinda use the tips of your fingers to hold it against the blade and your other fingers against the back of the blade so you can "feel" the angle.Just keep moving the file back and forth till the nicks are gone,and then do it again on the other cutting angle. The first time will be the hardest. Once you get the feel its a piece of cake. Just remember to follow the original angle. My first time it took about a half hour to do,now it takes 15 minutes. Slow and deliberate is the key. If you just start filing away in a hurry it wont work.