iFixit

Near the headphone jack, insert an iPod opening tool into the seam between the front and back of the iPod.

You may find it easier to carefully flex the putty knife downward in order to create more of a gap for the iPod opening tool, but be sure not to bend the corner of the rear panel!

Near the center of the display, carefully insert a metal spudger into the gap created by the iPod opening tool.

It is easy to create a noticeable bump in the rear panel here that is difficult to repair. When prying the tab free, try to have the metal spudger pivot on the edge of the rear panel rather than bending the rear panel outward.

Using the metal spudger, disengage the single clip on the top of the iPod.