I wired up a switch to allow me to play with or without the chimes,
This let's me play while the baby is asleep. To do this, I found
the one wire that goes to all three chime solenoids. This is the
ground (common) and can be used as a "master chime control". Either
cut the wire or disconnect it from it's source and put a toggle or
other type of SPST switch in series.
If you really want to get fancy, you can use the coin return plunger
to control the chimes.