Originally posted by Charlie
You can also change the switch WITH OUT TAKING THE CASE OFF the ESC. The switch has a small plastic case. Look on the back where the wires come out of the switch. There is a small silver tab, flatten that and untwist the wires. You can then easily slide the case off and unsolder the wires.
Unless the wires broke at the ESC case.
Yep, exactly what Charlie said is true!
I've used his advise and changed the switch multiple times when the inside mechanism stoped working and the unit always stayed on.
If you do decide to solder on from the board, make sure you're very good at soldering. The traces are small and long time with the soldering iron on them will melt the circuit board. Having copper braid or solder wick will also help suck the solder from the trace.