I have fitted a towbar on UK spec 2011 1.6 CRDi hatchback. I bought a 2nd hand Witter towbar, it was pretty easy except that the previous owner hadn't taken all the brackets off so I had to fabricate some more from steel angle. Hopefully you will have a towbar with all the right bits.
In Europe all towbars have to be type-approved so they must use the fixing points already provided in the chassis. The only possible modifications that may be required are to cut bits out of the rear bumper. I had to clean out the threaded bushes in the chassis using a tap, which I think was M12 fine pitch. Don't use a standard pitch tap you may find in hardware stores, it will wreck the thread. You need to clean out the rust and dirt that may have built up in the chassis attachments, otherwise it will be difficult to screw in the towbar attachment bolts and you could damage the threads on the bolts and chassis.
I used a wiring kit with a TBE7AS universal bypass relay, I wouldn't know whether you have similar things in Oz. For the UK, the towbar has a detachable swan-neck. It is not legal to use a fixed towbar because it partially obscures the view of the rear number plate.