There are two ribbon cables connecting the rear panel to the rest of the iPod. In the following step, be careful not to damage these ribbon cables.

Grasp the front panel assembly with one hand and the rear panel with the other.

Take a deep breath!

Gently (GENTLY) disengage the remaining clips on the rear panel by pulling the tops of the front and rear panels away from each other (think of the bottom of the iPod as a hinge), taking great care not to damage the ribbon cables holding the two halves together.