How to see an aurora in Australia - wait. And wait. In fact you will need to acquire a lot of patience right now with the sun at minimum activity. Until the sunspots return in good number and start cranking out flares it is unlikely we are going to see anything for a while.
While you are waiting, learn a bit more about what actually causes them and where to find the info on when to expect one. I highly recommend making
Spaceweather part of your daily online reading.
And if you can't wait - head north, like the others have suggested.
Oh, and the equinoxes are considered the best time of all during the year to see them, although no one yet knows why.