http://www.mustangworld.com/ourpics/fcar/news.htm search for MIL eliminators.
That link seems like it is down. Sorry
http://www.mileliminators.com sells them.
http://shop.store.yahoo.com/mustangweekly/lmr-44.html These work without cuting and soldering.
I have the sheets in the garage.
It is simple. A resistor and a capacitor.
Radio Shack part numbers
2721434 1 mfd Capacitor qty 2
2711356 1 megaohm resistor qty 5
One resistor inline of the grey wire.
One capacitor parallel across the black and grey wires.
Solder and heat shrink. I uses blue heat shrink to match the factory loom.
I could email you the instructions and wiring diagram.