aerides wrote:
I probably need to update my new 5Diii to get the enhanced autofocus capability. Is it just plug it in, click, and bang you're done? No weird questions that I wouldn't know off-hand about this or that? Thanks!
This should get you started.
Check your camera for your current firmware version. I believe the last one was 1.2.3 released in October 2013.
The newest firmware for the 5DIII can be found here.