install El Capitan on external drive

Emen Mali

macrumors newbie
Original poster
Jul 22, 2014
Chicago, Illinois
I'm trying to figure out what's the best way to get El Capitan onto an external drive (USB thumb drive) or actual SSD the MacBook Pro will boot from.

Right now There is no drive in the MacBook Pro (SSD) I am using Mojave on a Mac Pro 2009 but says I can't run the installer because its an old macOS. I've tried disk maker but keep getting errors.