Extending Your Visa
Assuming your passport is still valid and you are still 30 years of age or under you may be able to extend your working holiday visa for a second year. To be considered for the second year visa you must complete 3 months of agricultural work or 3 months of work in a remote area of Australia. Woofing is also accepted assuming it fits into the above stipulations.
For more information on extending your working holiday visa visit the Australian Department of Immigration website at http://www.immi.gov.au