To the bottom? I drilled just regular holes. I used M3 6mm screws thru the bottom plate to fit the amp and psu. i.e. bottom of the EVAL1 and psu have standoff "nuts" that accept those screws. I used button head screws, like the ones in the picture:Right, I don't have such fancy tools, just a regular hand-held drill which will not be as precise. But those holes you drilled, were you using a type of drill bit that inserts a tread so you can just screw it in? Or do you have to use a nut that goes to the outside of the case?