You could open the drum kit in Beat Buddy Manager and lower the volume on all the piano notes, or you can export the .sng part as a midi file, and then, in a DAW, select all of the piano notes, and reduce the velocity.
You could open the drum kit in Beat Buddy Manager and lower the volume on all the piano notes, or you can export the .sng part as a midi file, and then, in a DAW, select all of the piano notes, and reduce the velocity.