The first step is to update your dog as a neuter in the Dogs Australia database. Please contact your local state office for more information on how to update the dog’s registration to reflect its neuter status. https://dogsaustralia.org.au/contact/member-bodies/
When the dog has been registered as a neuter, you can then update the dog's details to match the Dogs Australia database. This article will tell you how to update the dog's details so that they match the Dogs Australia database. https://showmanager.zendesk.com/hc/en-us/articles/202337574