If you've used the install wizard and installed your eZ publish installation in e.g. http://localhost/news then your admin site will be availble on http://localhost/news_admin. We automatically make the admin interface available with _admin appended to your user site, if you've not configured it to be something else.
I have tried http://www.olmc.nsw.edu.au/magex/ezpublish_admin/ but get page not found.
The files are in the 'ezpublish' directory. Can I rerun the setup wizard?
I have solved this bt deleting the installation adn re-installing and tkaing notice of the choices I made during the install.