Open androidfiletransfer.dmg (The next time you connect your device, it should open automatically)
Plug your AT&T TREK HD Tablet into your computer using the USB cable. Note: If you are asked to select a USB connection on your AT&T TREK HD device, choose Media device (MTP).
Make sure your AT&T TREK HD device screen is unlocked.
From the computer, drag Android File Transfer to Applications.
Double click Android File Transfer.
Browse the files and folders on your Android device and drag and drop any files desired including photos, music, and other documents saved on either the phone storage or microSD from the tablet storage to the computer storage.