Step 1: Materials
(x1) Audio output transformer (radioshack #273-1380)
(x2) 1/8" mono jacks (radioshack #274-0251)
(x1) 3" x 2" x 1" project enclosure (radioshack #270-1801)
(x1) Piezo transducer (radioshack #273-0073)
(x1) 6' stripped-end audio mono cable (radioshack #42-2434)
(x1) Mini audio amplifier (radioshack #277-1008)
(x2) 6' audio mono cable (radioshack #42-2420)
(x1) Assorted shrink tube (radioshack #278-1627)
(x1) Audio player with output jack
(x1) Roll of double-sided tape
Step 2: Solder
Solder the green wire from the audio output transformer to the ground tab on the other mono jack, and the blue wire to the signal tab. This will be the output jack.
Trim the black wire to remove any exposed uninsulated wire.
Step 3: Holes
Drill both of these marks with a 1/4" drill bit.
Step 4: Install
Finally, mount them firmly in place with their mounting nuts.