The Live View part of the manual is 7 pages with pictures, JD. It's one thing to read and not understand, but to not read at all
You could have had your answer much faster.
Custom Function III; 6 - AF during Live View Shooting :
Enable
You can autofocus anytime you want with liveview.
Push the
AF-On button and it will drop the mirror and reaquire focus. When it beeps let off the button.
I highly suggest reading the manual of this piece of machinery. At least Live View and Custom Functions.