I,ve just done this conversion in my m4 escort cabriolet.
my donor car had PATs So I just followed the wires from the ecu up to the steering colomn and removed the whole thing. basically it is a ring shaped sensor around the ignition barrel that senses the proximity of the chipped key so the ecu only functions when the correct key is in the ignition. so to cut a long story short I taped the key to the sensor ring and put it with the ecu in the glove box, works fine.