The shiny rear half of your iPod case.
Insert a plastic iPod opening tool in the seam between the white plastic front and metal back of the iPod. It helps to hold the iPod at top and bottom as shown and squeeze to help pop out the edge. Once you've inserted the tool, run it along the seam to free the five tabs holding the iPod together.
Continue to run the opening tool along the side of the case until all five tabs have been released.
Work around the corner of the iPod and release the two tabs holding the iPod together near the dock connector.
Free the five tabs holding the iPod together on the other side. You may be able to free the tabs by gently wiggling the front panel of the iPod.
Lift the rear panel away from the iPod.