Can I change the plug on my tool purchased in the USA

No, the plug cannot be changed and tool used in Australia. Due to the difference in voltages between the US and Australia Festool are not able to change the plug.

If the plug is changed on a US sourced Festool item to an Australian plug and used on the Australian 240v system, Festool advises that damage to the tool may result and Festool cannot guarantee the tool or provide warranty to any tool that is modified like this or indeed purchased outside Australia.

It is technically possible to modify US sourced Festool items to run in Australian however in most cases this would be more expensive than purchasing a new tool.