To replace the battery on your Piezo-equipped PRS guitar, access the clip-door on the jack plate and carefully remove the battery compartment. Be careful not to disconnect the red and black leads connecting the battery compartment to the PC board.
Press the old battery down and away from the connection points of the compartment and remove the old battery from the metal clasp. Insert a new 9-volt battery into the clasp and press upward into the connection points to connect the battery.