Dave - It is a fairly straight forward process.
Your supplier in China will crate the machine and deliver it to the ship.
They should then send you the documentation - including Bill of Lading, fumigation certificate etc.
You will need to contact a Broker/ Receiver in Melbourne before you order the machine. They will take care of all Customs requirements. As soon as you receive the documents from China - forward them immediately to your Broker. They will also organise forwarding your machine to Tasmania.
If you do not know a Broker i suggest you contact Loch M Fraser. They take care of our Mustang importing and we have never had a problem with them. They should be able to give you an idea of the costs at this end, which will depend on whether it is a Full container load or Less than container load.
What size machine is it?