Best option for disposal:
Power tools are classified as e-waste and can be dropped off for free at the Drysdale or Geelong Resource Recovery Centres.
It is against the law in Victoria to put e-waste in your kerbside bin.
Other tools that are made of mostly metal can be disposed of for free at the Drysdale or Geelong Resource Recovery Centres in the metal recycling bin.
Otherwise:
You may be able to have your tool repaired through the business you purchased it from, or a specialist repairer.