You've most likely got a leaking water solenoid valve.
But to answer your question, the water level adjustment is on the right-hand edge of the control module.
Open the door to the unit, then pull the cover off the front of the icemaker unit inside, in the upper left corner.
You'll see a tan/gray-colored plate with a white gear wheel in the center of it. Look along the right-hand edge of this gray plate. About midway down, you'll see a tiny nylon screw. This is the water level adjustment. It only has a range of one complete turn. You can turn it up to 1/2 turn in either direction - no more than that, or it will "pop" out and you'll get no adjustment at all. Turn it up to 1/2 turn CLOCKWISE, to reduce the water level inside the mold. This will adjust the water level in the ice mold up to 20 cc's. You don't get much of an adjustment, and rarely ever have to change the adjustment.
More likely, as I mentioned at the beginning, water is leaking through the water valve, and causing the mold to overflow. It that's the case, replace the water valve.
