Use a spudger to remove the plastic plate from the bottom of the player. Snip the wires using a wirecutter. Be careful not to nick the battery and cause battery acid to leak everywhere. Remove the two screws on the bottom of the device with a Phillips head screwdriver. Use the spudger to push the USB port on the bottom of the device inward.
The plastic LCD cover and the key pad will now be free; they were held in place by the tension between the case and the internal circuit board. Hold the device firmly between two fingers. Be sure you aren’t holding down the top of the device; the circuit board will slide out of the shell through that end. The battery is the large packet-like component beneath where the buttons would be.
Gently lift it off of the circuit and move it off of the board, allowing access to the wires.