Shorten a trolling motor shaft

[HLS]

I may be the most NON-mechanical guy out here. But I chopped my trolling motor with no problems except there are TWO black wires under the cover and, of course, I mixed them up the first go-round. Works Like a champ. Now I'm water testing a jump-start charger as my main trolling motor battery for a kayak. Trolling Motor Battery Charts (+Run Time Calculator) - TrollingMotorPro has a great trolling motor/battery run time chart.

Thanks to all who said, "do not take off the motor head." Seems there is a water tight seal that we should not mess up.