Tim's Step by Step Instructions and Video 

• Windows: Creating a MicroSD card to load LeJOS for Quorum on an EV3 Robot
• MAC OS
• Creating the LeJOS SD card using the Linux OS.

Quorum Website Instructions for installing leJOS on your SD Card. 

leJOS Wiki  Instructions  -  Advanced users. 

Buy a micro-SD Card with leJOS fully installed and ready to use from the menu to right.