How to make a bootable USB Stick with El Captain
- Download der OS X El Capitan installer into the Application folder via App Store. The installer will remove itself when you run the installer, but you can download the installer again.
- Format an USB Stick (> 8Gig) with Extended (Journaled) HFS+ with the name "foobar" or something you like.
- Go to the Terminal and type
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/foobar --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app --nointeraction
How you have a bootable USB Stick.
You can choose the boot disk with system preferences or by holding der option key.