Mute switches?

[mse72]

I'm just getting started with circuit bending, I have two old casios (an MT-36 and a MT-68) that I'd like to at least add some mute switches to for the different drum parts and hopefully the chord accompaniment.

I found the pins on the accompaniment chips for each of the drums, the bass and the three chord parts but I'm not sure how I'm supposed to wire in the switches.

Do I have to cut the traces before they go to any other connections on the pcb or is it possible to cut them further down the line where space isn't so cramped?

Also, for anyone that has done a mute for casio chord parts, how do you make it mute all three individual chord notes with one switch?

Does anyone have a photo of a pcb for these (or similar models) where they've wired in mute switches?