The iPod case is now open, but don't separate the two halves just yet. There is still an orange ribbon cable connecting the headphone jack to the logic board.
Open the case like a book with the dock connector at the top, and lay the rear panel next to the front half of the iPod.
Use a plastic tool or your fingernails to carefully disconnect the orange headphone jack cable. Be sure to pull straight up on the connector, not the cable itself.
The headphone jack connector is unusually tall. When prying, be careful to not separate the lower, plastic part of the connector from the ribbon cable. Pry between the connector and the socket, not between the two halves of the connector.
When reassembling your iPod, be sure that the plastic hold switch mechanism is synced with the hold switch on the logic board. The switch on the board is a small black nub that sits in a slot on the hold switch mechanism.