No disrespect, but why would you want to do that? A simple pouch on a sheath is a much simpler and logical solution, IMO. Removing the scales, hollowing them out and replacing the tubes with bolts is an answer to what question?
Theoretically, you could hollow out the scales with a dremel (wearing a respirator so you don't breathe the toxic dust) and reattach them with chicago bolts, but then you would need some sort of screwdriver to remove them. A screwdriver which would occupy about the same amount of space in your kit as you gained by hollowing out the scales in the first place. I bet somebody has done this already, though I've personally never seen it.