i went to the breakers yard and cut the wiring off another range i used new plugs with about 6" of new wire, the ecu is situated behind the battery under a black cover.
get yourself some 3mm heatshrink too, to do the job properly, i dunno it if helped but i had the batery off the night before to charge it and left the motor plugged into a battery pack.
the car was without battery power for at least 2 hours whilst i was soldering so i recomend u do the same, maybe to help with some kind of reset, im unsure
all i know is that it worked for me, the 3 plugs in question are a large black one, a large red plug and a smaller black plug.
if you need any more info then just say