It's a different installation method to previous builds. You have to download and install os_x_software_update_seed_configuration_utility first from the mac dev center. This opens the mac app store but gives you more updates than those publicly available. OS X Mountain Lion 10.8.3 now shows up and you have to download it from the mac app store. The dmg or pkg file is not available directly from the mac dev center anymore.
If you want to keep the mountain lion installer then after it downloads from the mac app store but before installing the update go to /Library/Updates and find the file OSXUpd10.8.3.pkg and copy it somewhere. You have to do this because after updating the installer deletes itself!
What a nuisance! Why not just put the dmg on the mac dev center?
If you want to keep the mountain lion installer then after it downloads from the mac app store but before installing the update go to /Library/Updates and find the file OSXUpd10.8.3.pkg and copy it somewhere. You have to do this because after updating the installer deletes itself!
What a nuisance! Why not just put the dmg on the mac dev center?