First, remove the top filter cap. quarter turn.
Remove the three screws from under said cap.
The rubber switch cover will come off of the on/off switch pedal there. pull off and set aside.
undo the two clamps and remove the motor (chrome) section from the base.
give the handle a tug and the chrome cap should now come off and allow you access to the wiring and motor/switch.

optional side note: at this point you may want to replace the sponge filter around the motor too.

Remove the cord from the unit and rewire to the same spots the old cord comes out of.
reverse the instructions to put the machine back together.