Removing a piezo transducer from a reference design
A piezo with three connections shown in the circuit on page 21 is used in a self-ocsillating piezo circuit. The smallest electrode (the one connected to R3) is the sense electrode, which provides feedback to the input (that's what the "FEED" means: feedback).



The image is from the block diagram on page 2. The horn driver signal from the level shifter will just be an enable signal, so that's DC. When high the AND gates work as inverters, and you have a typical 2-inverter CMOS oscillator. When the driver signal is low the outputs of the AND gates are permanently high, and therefore HS and HB both low, and the circuit won't oscillate.

To disable the buzzer you simply can cut the connection to FEED, and neither HB nor HS will be driven. You won't need to remove any components.