This is a step-by-step guide to scalloping your fretboard. Scalloping is the removal of wood between the frets (usually from fret 14 upwards). Some players, like Yngwie Malmsteen, favour a scalloped fretboard as it is supposed to make it easier to play fast.
The tools needed are: a round file and sandpaper for wood removal and a Dremel for polishing.
Link: DIY guide to fretboard scalloping