"turn the AC30 to 10, use a deaky amp and a volume pedal" :)
I remember he played it note for note with a volume pedal fading in. The different sounds you get with the phase-shifted pickups, and a treble booster and the amp in full volume.
You will need the feedback of the guitar (just like in the guitar bit of YTMBA) when you stand in a place of the room, where the guitar feeds back from the amplifier, so you just tap on the fingerboard to get the tone.
Playing with a coin (you can use a metal-coated or stone-pickup too) lifts the overtones/partial tones (you have a lot of them, altogether they form the whole tone), and it is also a question of palm muting, to erase overtones.
Special thanks to Arif Mardin who arranged and produced some hot and spacey horns on "Staying Power" ;-)