1. Plug phone into computer with provided USB cable.
2. Pull notification blind down on Droid, push "USB connected" and then "Mount".
3. The SD card should appear as an external USB drive in "My Computer" if in Windows or on the desktop if in Mac OS.
4. Create a folder on the SD Card named "Music" if it doesn't already exist and drag and drop anything you want in there.
5. (not absolutely necessary but recommended) Safely remove hardware using the system tray icon in windows, or drag the SD card drive to the trash in Mac OS
6. Unmount in the notification blind.