pull the knob off theres a "o" shaped ring that goes down the center shaft, using an electrical screw driver just put it in the hole locate it in one of teh slots on teh "o" ring and turn it clock wise to tighten the thing up.... or from behind the dash ( take out the pocket to the lower right of the dash under the steering wheel) theres a plastic nut on the back of the control switch just do it up finger tight.