To open the uninstaller, double-click it in the Downloads window.
Use a USB flash drive or other secondary volume to create a bootable installer. If you are using Mac OS X 10.7 (Lion), click the Downloads icon displayed on the browser. How to completely uninstall a program or application in Mac OS X Mavericks, Mountain Lion or any OS X operating system.
Use the App Store to download and install the latest macOS or an earlier macOS.You can also use these methods to install macOS, if the macOS is compatible with your Mac: If you've just erased your entire startup disk, you may only be offered the macOS that came with your Mac, or the closest version still available.If the Mac logic board has just been replaced, you may only be offered the latest macOS that is compatible with your Mac.Or you can use Option-Command-R during the startup process to be offered either the latest macOS that is compatible with your Mac, or in some cases the macOS that came with your Mac or the closest version still available. On an Intel-based Mac, you can use Shift-Option-Command-R during the startup process to be offered the macOS that came with your Mac, or the closest version still available.When you install macOS from Recovery, you'll get the current version of the most recently installed macOS, with some exceptions: Make sure you are logged into the same iTunes account you used to purchase macOS Server. Open up the App Store on whichever Mac you are attempting to install macOS Server on. When the new owner starts up the Mac, they can use their own information to complete the setup process. Download the older version of Server on the Mac running an older version of OS X. If you're selling, trading in or giving away your Mac, press Command-Q to quit the assistant without completing setup. When the installation is complete, your Mac may restart to a setup assistant.
Your Mac may restart and show a progress bar several times, and the screen may be empty for minutes at a time.