A piezo guitar pickup, unlike a regular magnetic guitar pickup, has a higher frequency range which creates a unique sound when it is run through an amplifier. It also cuts down on excess noise like hum and feedback. If you have just purchased a piezo pickup, you may be staring at the body of your guitar, wondering where the thing goes. The good news is that the process for installing a piezo pickup is relatively straightforward and can even be used in conjunction with other electric pickups on your guitar.
Use the tuning pegs on the head of the guitar to loosen all six of the strings. Make sure there is enough slack so you can fit your whole hand under the strings on the body of the guitar near the bridge.
Insert the tip of your flathead screwdriver in the seam where the side of the bridge meets the body of the guitar. Then gently pop the bridge of the guitar up to remove it. The bridge is the rectangular component that the strings connect to in the middle of the body of the guitar.
Drill a 3mm hole on the very bottom of the indentation where the bridge sits. Then slide the cable that connects to the end of the pickup through the hole in the bridge.
Place the end of the pickup just above the hole in the guitar. Then replace the bridge and press down firmly on each side until it snaps securely back in place. The pickup itself is so thin, the bridge won't disturb it.
Fit the strings back over the bridge saddle (piece of plastic that holds the strings in place) and tighten the strings. Tune the guitar using the tuning pegs and you are done.