Skip on down to the menu.
Hidden Menus on VZW Samsung Galaxy S3.
My source was this forum.
Need to access hidden menus to change usb mode.
Turn on hidden menus
Bring up the dial pad and type in *#22745927 but don't hit the send dial button. It should bring up a menu choice after you type in the final "7".
Turn hidden menus on.
Changing the usb mode
Bring up the dial pad again and enter *#7284#
Choose the appropriate usb mode.
2013-10-08, T. Sneddon