i had to do this with my Gibson, the high E all of a sudden was too low, it wasnt like that when I bought it. anywho I took some baking soda, dipped my finger in it and smahed it into the slot and blew off the excess, repeated and then applied a small drop of super glue. Worked like a charm and you cant hardly tell but for some sheen on the nut I got lucky and did not have to file it, it was just right.