The five plastic clips along the side of the Zune lock onto small aluminum tabs cast into the inner chassis. To separate these clips, the plastic portion must be pushed toward the inside of the Zune while prying the inner chassis up off the front case.

The two plastic clips attached to the front case along the top edge of the Zune (second picture) simply clip onto the inner chassis. To separate the top edge, carefully push each clip away from the inside of the Zune while prying the inner chassis off the front case.