This is how I did it. This is how my "harness" looked when put together.
As the description above states, I then unplugged the blue with white stripe wire in this pic.
I then connected the 2 spades in place of the blue with white stripe wire. I then pulled the ground wire off at the bottom of the tach, plugged in the piggy back spade in the original ground's slot, and then plugged the old ground wire into the piggy back.
I have a set of ETarga's LED's in my indicators. At first, only 1 indicator lit up. Playing around, I don't think I had 1 of the indicator LED's plugged all the way in. I pulled them out but then pushed them in as far as I could and they both worked, but they then worked in opposites, so I reversed the live end of the circuit on the indicator bulbs and everything works perfectly.