Geocaching Australia

Hi, I am in Queensland and I am new to the GPS world and to caching...A couple of questions.... 1. I have a new Sportrak Map ... and it is loaded with US base maps.... anyone know how to unload and re-load with Aussie data... or can I just add the aussie data as well??? 2. I received a message via e...

I have a new Sportrak Map...its loaded with USA maps....can anyone guide me as to how to get rid of the US data and reload with Aussie info.....???
Another thought...is it possible to simply load the Aussie data on as well as the US data...there is still 4mb of space on the gps???