When finished teaching, pull up XPanel from where it is minimized in the bottom left corner of the screen. Click Lab Mode.
Quit Xpanel from the dropdown menu at the top left corner of the desktop as shown below.
Click the stop button on the AirMedia display.
Quit AirMedia from the top right menu of the desktop.
Shut down the computer using the dropdown menu from the Apple icon at the top left corner of the desktop.
Click Shut Down.