There's actually no need to involve the PCB at all. What I did was just keep the Hori microswitches attached, as they're exactly the same size and shape, and fit right into the Sanwa base. I did some testing, and couldn't feel a significant difference between those and the ones that came with the Sanwa. Alternatively, I could have detached the wires on the Hori switches and re-soldered them directly onto the Sanwa ones, bypassing the attached PCB. If I get brave and decide to replace the buttons at some point, I'll probably attach the sanwa switches with the wiring harness, as I'll have to remove the circuit board anyway.
