How do I update my Mac's operating system?
To update the software on your Mac, run Apple Software Update:
  1. Click the Apple menu and choose Software Update.
  2. Click Continue should the Software updates are available for your computer message appear. Review list of available updates and check the box next to each one and click Install.
  3. Restart the computer if prompted. You may need to run Apple Software Update multiple times in order to fully update your computer.