There are various ways of getting there but one we chose was to rent a 172 from Air Australia at Jandakot (tel: +61 9 332 5011). Rotto has a windsock at each end of the runway, because the wind is often in different directions at each end due to the hills. (Not as bad as Skagway, Alaska, which needs a windsock in the middle as well as one at each end.)
The route taken is shown below: yes, you are allowed to do a 360 over the city centre (and we would have been able to do a missed approach at the international airport for free, but I decided to "give that one away", not having flown for about seven years and not wanting to look too silly right in front of the tower).
There are some tame quokkas in the bushes just outside Rotto's airport building, and the airport keeps a tin bowl for feeding water to the quokkas so that they come out where you can see them.
Perth city centre from not-very-high-up in a 172