super quick instructions.
1) buy a stebel airhorn **WITH** wiring kit/relay, ebay is a good place to start
2) you going to need some steel plate about 2 or 3 mm thick about 10mm or so wide about 20 centimeters or so long, maybe less
3) one you get the horn look at it and drill a hole in the steel plate to fit a both thru it and bolt it to the top of the horn in the mounting hole
4) remove the fairing off the bike, mount the other end of the steel plate to a bolt that holds the motor in and make sure you have enough gap between the horn & fairing & motor to put fairing on. there wont be much room left but it will fit, mine does.... just
5) connect the wiring to the air horn, battery and disconnect the wires to the stock horn and connect to the relay wiring. now what will happen when you press the stock horn button power will travel along the new wiring harness after being engaged by the relay and power the horn.
6) once tested, put a few zip ties on cables to stop them falling down and put fairing back on 7) sit back , relax have a cold beverage and enjoy your handy work