Installing OS X has never been easier than in Yosemite. In this article, we’ll look at upgrading a Mac from OS X 10.9 (Mavericks) to OS X 10.10 (Yosemite). The first thing you should do is clone your system. The second thing you should do is make sure you have a good backup. The third thing you should do is make sure you can swap back to the clone should you need to do so and that your data will remain functional on the backup. Once you’re sure that you have a fallback plan, let’s get started by downloading OS X Yosemite from the App Store. Once downloaded, you’ll see Install OS X Yosemite sitting in LaunchPad, as well as in the /Applications folder.
Open the app and click Continue (provided of course that you are ready to restart the computer and install OS X Yosemite).
At the licensing agreement, click Agree (or don’t and there will be no Mavericks for you).
At the pop-up click Agree again, unless you’ve changed your mind about the license agreement in the past couple of seconds.
At the Install screen, click Install and the computer will reboot.
And you’re done. Now for the fun stuff!
