If you're concerned about the placement of the locating holes, try inking up the area on the bars with a black Sharpie pen, mount the control loosely where you want it, and gently and with small movements, rock the control back-and-forth on the bar to remove the ink where the pin sticks out. That's where you drill the hole. Since chrome is really hard to drill through, I would recomment that you centerpunch the mark, and using a grinding tip in the Dremel, remove the chrome from around the centerpunch mark before drilling. Where the wires exit the bars, you need an elongated hole or slot to get the wires through, and this is where a carbide burr bit in the Dremel comes in handy. The slot I made was around 1/4" w x 7/8" long. JUST BE REALLY CAREFUL THAT YOU ROUND THE EDGES INSIDE THE BARS WHERE THE WIRES ENTER AND EXIT.
Steve F