Each of the bells has two wires attached to the coil. They are spade connectors which should easily pull off. Pull off only one connector on each bell to minimize a possible short circuit. Put a bit of electrical tape on the wire connector to make absolutely sure it can't touch anything. I'd pull off the black wire which is common to all the coils.

I think Hurdy Gurdy has three bells, and the spade connector approach will work for one of them, but not so sure on the other two.

The 3" bell that's bracket mounted by itself probably has the black wire soldered to the coil lug, and the spade connector on the colored wire only. That one can just be pulled off and set aside.

Another 3" bell is mounted below the 0-9 unit, and is struck by a clapper attached to the stepper. It won't have a spade lug that can be detached. But there the bell is just held in place with a bolt and nut, right to the bracket. You can either remove the bell, or remove the clapper (but keep the parts with the game - these tend to get lost).

The last bell is the 100 point bell and that's displayed right in the backbox, to be 'struck' by the monkey. That one might just be a coil, but I don't recall for sure.

Of course for the coil-driven ones, the plunger can just be removed too (nylon-tip plunger inside the coil). That won't work for the 0-9 bell though.

Here is another option.
You could also glue a small piece of foam to were the striker hits the bell. This will dull the sound and yet when playing the striking will still be slightly noticed. Gluing foam to a bell is reversible, as is de-soldering or cutting a wire.

Your such a gurdy Gerry. Get them done so I can come over an play next week while I'm out there.
I am having fun with Frodd over on rgp.

wow hurdy must be one loud ass game, your BH with the sub is pretty loud

"Hurdy Gurdy" is an add-a-ball game, and so does not have a 0-9 unit with the mechanically struck bell. All three bells are electrically operated. I forgot that the 100 point gong is the monkey unit, and the coil is located inside the bell which is inside the lightbox of course. The monkey's hammer doesn't actually sound the gong; it's just an animation. The gong is rung by a coil and plunger as on all other games with the 5" gong.