Type or paste one of the following commands in Terminal.

Open Terminal, which is in the Utilities folder of your Applications folder.

Connect the USB flash drive or other volume that you're using for the bootable installer.

You will create the bootable installer from this app, not from the disk image or.

It installs an app named Install OS X El Capitan into your Applications folder.

Inside the disk image is an installer named InstallMacOSX.pkg.Download using Safari, and open the disk image on a Mac that is compatible with OS X El Capitan.The installer for OS X El Capitan downloads to your Downloads folder as a disk image named InstallMacOSX.dmg. Enterprise administrators: Download from Apple, not a locally hosted software-update server.Download on a Mac that is using macOS Sierra 10.12.5 or later, or OS X El Capitan 10.11.6.Download on a Mac that is compatible with that version of macOS.If the installer opens after downloading, quit it without continuing installation. The installer for macOS Monterey, macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra downloads to your Applications folder as an app named Install macOS.

Mac disk image thumb drive