Here's a short video showing the steps required to change the switchboard in a Submarine. This repair is suitable for when there is a fault with either the switch or the 3.5mm connector.
It is a relatively easy repair. The only tool you will need is a pair of pliers or small adjustable spanner. The only part that is not straightforward is the adjustment screws having a left handed thread. This means that when you are removing them or putting them back into the die cast housing the turn will be in the opposite direction to what you expect.
Best of luck. Of course if you do have any issues or questions I'm always here to help.