iFixit

With the iPod opening tool, gently lift the brown tab of the headphone ribbon cable connector. The tab will rotate up 90 degrees, releasing the ribbon cable.

Using your fingers, pull out the headphone jack ribbon cable.

The front and back of the iPod should now be completely separated.

Use a small iPod opening tool to release the black hinge holding the hard drive ribbon cable. The tab will rotate up 90 degrees towards the logic board, releasing the ribbon cable.

Use your forefinger to hold the ribbon cable in place; disconnect the drive from the ribbon cable.

Make sure the hard drive rubber side bumpers are attached to the drive being installed. Use the hard drive rubber side bumper installation guide to accomplish this task.

If necessary, the blue foam padding on the hard drive might also need to be transferred to the replacement drive.