If you plan to live in a foreign country, you need to have a valid Passport. My passport was due to expire next February so I organised to have mine renewed through the Australian Embassy here in Thailand.
These links are valid as of the 30th of July 2020. Depending on when you read this description will have an impact on the validity of the links as the internet is constantly changing.
Create an account on the Australian Passport Office and fill out the form
Have a professional photographer take your passport photo
Create an appointment to present the printed form along with 3 passport photos at the Australian Embassy in Bangkok and go pay the fee.
Once the renewal process has been completed, you will need to go back to the embassy to pick up your new Passport and have the old Passport cancelled. You can choose to have the new passport delivered by registered mail but there is a technical caveat that might concern you in that they will need to cancel your passport when you present your documents. This means that you will be in a foreign country without a valid passport for approximately 3 weeks. It is your choice about that risk assessment but they did say that there is usually no problem.