No need to fear when it comes to lowering the depth of your string slots at the nut. This method is so easy even a child can do it!

BTW, these are not files. These are jeweler's piercing saw blades. You can find them on Amazon by searching: GERMAN STYLE JEWELERS SAW FRAME with 144 ASSORTED JEWELERS SAW BLADES

Too, this video may help:
   • Overcut Nut Slot? A Fix Anyone Can Do