Thanks for your question. Hypothetically it is possible that a group of people could 'overthrow' the Australian Government; however it is important to note that Australia's political system since federation has always been characterised by stability. This stability would make a military coup style of take-over – as has occurred in other countries – highly unlikely.
The Australian Constitution makes no reference to 'overthrowing governments' or 'tyrannical' behaviour.
The Australian system of government is determined by the Constitution – this system was established at federation in 1901. The Constitution enables the election of the Australian Government, by the Australian people. Once elected, there are many ways the Australian Government can be held accountable for their actions. For example, scrutiny occurs by the Opposition within Parliament, and through the committee system. The media also plays an important role in holding the Government to account. Ultimately, the fate of the Australian Government is determined by the Australian people when they cast their vote at a federal election.