How to Enable Disk Mode on an iPod
- 1). Launch the iTunes application on your Mac or PC computer.
- 2). Connect your iPod Classic, Nano or Shuffle to your computer using the iPod USB cable.
- 3). Click on the name of your iPod in the "Devices" list on the left side of the iTunes window.
- 4). Go to the "Summary" tab at the top of the iPod configuration screen.
- 5). Check the box next to "Enable Disk Use."
- 6). Press the "Apply" button in the lower-right corner to save the settings and enable disk mode. You can now transfer files to your iPod's hard drive using the Finder on a Mac or Windows Explorer on a PC.
- 7). Click on the "Eject" symbol next to the iPod's name to safely eject the iPod before disconnecting it from the computer.
Source...