I just finished doing this mod. I love the new lighted zhp version. The whole process goes pretty much as the DIY. The hole I drilled was 9/64. It's the smallest hole that big enough to pass both wires through. The white/beige color thingy at the bottom of the knob is just a foam ring, I removed it instead of drilling through it and put it back in after I fish the wire through. I also hollowed out the zhp knob and put in fishing weight inside in an effort to try to retain the weight. Not much difference in the end but the zhp knob is 190 gram after everything is done. I think it starts out at 180 gram. The key is to take your time. I don't have a drill press so everything was free handed with a dremel and a drill. Thank you once again for the OP and others that have contributed to this DIY.