How do I set a Yongnuo YN600EX-RT into optical master mode to trigger a Canon 430EXII?

I just got a Yongnuo 600EX-RT and my biggest gripe is their manual! I'm trying to figure out how to get it to trigger my Canon 430EX II and I can't figure out how to set it to Optical Master mode either through its own menus or those in the camera.

When I go into the camera, the menu option is there, but it only wants to go into wireless mode, every time I click "optical" it just returns to "wireless".

I can't for the life of me figure out how you change this setting on the flash itself.

Any guidance would be very much appreciated!

Additional info:

I can get it into Master Wireless mode, just not Master Optical. I have a Canon 70D. Pressing the lightning button just cycles through modes....either Master (1 option) or Slave options or Normal mode.