Apple has released a new operating system in beta called Yosemite and anyone with a Mac can try it out. All you need to get started with this operating system is a Mac running OS X Mavericks, 2GB of memory, 8GB of disk space, and an Apple ID. Of course, you'll also want to back up your system before performing the install, just in case something happens. Then follow these instructions to install Yosemite on your Mac.
1. Register on the OS X Beta Program website by clicking Sign Up then signing in with your Apple ID and agreeing to some terms. Be sure to do this on the machine you want to install Yosemite. When you read and agree to the terms, you will get a redemption code that allows you to download and install Yosemite.
3. Once Yosemite has downloaded, you'll be asked to sign in with your Apple ID.
4. Agree to the terms and conditions.
5. Select "Turn on FileVault disk encryption" to secure your data. For more security, uncheck “Alow my iCloud account to unlock my disk.”
6. If you are using iCloud on any non-Yosemite device, choose “Not Now” when asked if you want to upgrade to iCloud drive. If you don't do this, you may lose files that were stored on iCloud.
7. Note any incompatible software so that you can check for updates later.
8. Use the Feedback Assistant to report any errors or problems you may find with Yosemite.