To install the new beta, you must be part of the Apple Beta Software Program. If you’re not you can sign up, but remember, it’s beta software and it’s possible that you’ll encounter bugs and problems with your apps and hardware, which is why you should provide feedback when using the beta. For folks already running the El Cap beta, you can update the OS through the App Store.
The few obvious changes to the software include:
Have no clue as to what this beta stuff is all about Read our El Capitan beta FAQ.
If you’ve been using the beta and you don’t want to anymore, you can revert back to Yosemite.
Don’t want to try the beta, but you want to learn about El Capitan’s new features We have a bunch of first look articles you can read:
Roman Loyola