Opps, not actually a one wire alternator, two wires.
I had a quick look but can't find the link anymore. I remember that I wasn't able to follow the link step by step anyway, because my connections and my alternator were different to the ones that they were writing about. From reading it though I got the basic gist of how it was supposed to work.
The two female spade plug that went into the original alternator did fit the new alternator, but the new alternator only had one corresponding male spade connector. I disconnected the external regulator, and on the engine side of the now disconnected regulator plug I bridged the blue wire (warning lamp) to the yellow wire (which is the female spade that is now hooked into the alternator). I then wired up the big fat battery wire to the new alternator the same way it was with the old one, and bob's your uncle. It appears to work fine. When you start the car the charge light stays on, but then you blip the throttle it turns off and stays off. Also haven't had any problems with the battery, voltage regulator reads about 14V when driving around.
It's a Bosch K1 alternator, the casing says it's an 85A unit.