Apple had seeded the golden master (GM) of its next OS X 10.11 El Capitan to developers and beta tester members following the media event in San Francisco. As a registered member of Apple Beta Software Program, I received an email from Apple saying that they are pleased to give me access to OS X El Capitan GM Candidate.
Thank you for participating in the Apple Beta Software Program. Your feedback and usage of the OS X El Capitan public beta has helped us make this release great. We are pleased to give you access to the OS X El Capitan GM Candidate.
If you are currently testing OS X El Capitan, please back up your Mac and do the following to install the GM Candidate. Go to your Purchased tab in the Mac App Store and click the Download button next to OS X El Capitan GM Candidate. Then click Continue to download the full OS X installer. When your download finishes, the installer will automatically launch. Follow the onscreen instructions to complete installation.
The email also contains how to install the GM candidate by just going to Purchased tab in the Mac App Store and click the Download button next to OS X El Capitan GM Candidate. Then click Continue to download the full OS X installer.
Download OS X El Capitan GM Candidate
But when I tried to follow the guide, the Download button is grey out so it is not clickable. Installing from Mac App Store has failed.
Fortunately there is a website that provide the OS X El Capitan image so we can download and install it. Yes you can download the OS X El Capitan GM or other OS X Betas from imzdl.com/osx.html.
Even if you are not a developer or beta tester member, you can still be able to install it.
Once download it, double-click the installer and follow the on-screen installation steps.