We have a 33, and the switch panel is horizontal, beside the chart-table, just to the left of the companionway down to the saloon, forward of the wheel. I unscrew all six(?) screws and gently prize the panel upwards. There’s not a lot of spare wiring, so it can’t be pulled up and out, but can be tilted over to one side to get access to the bottoms of the switches.
But that’s a 33, not a 331, sorry.