Ralph,
I've had mine apart several times, it's kind of a pain. Thinking.... I may have to run out to the car and grab my machine. There are no screws that hold the contol box to the handle. Remove the four screws holding the control box together. The front part will slide off the front of the handle when you remove the upper shaft, coil, and I think the camlock. The only wiring on the front part is the speaker and there is a plug to remove it from the main PC board. The wiring from the back half of the control box goes through a hole in the handle, you'll need to remove the handgrip cushion and take the handle apart. Most of the wiring is siliconed to one side of the handle so unless you break it all loose you still won't be able to seperate the control box. Not the best design, IMO. And putting it all back together and getting the wiring tucked away to close the control panel up is a bit tricky too. But it can be done. I broke the 1/8 headphone jack awhile back and replaced it with a 1/4 phone plug dongle, much sturdier.
Good luck
Chris