How do I replace a fan blower switch?

How do you know its the switch?I would hate to see you replace the switch for nothing.

You have to remove the heater control unit first and if switch is available replace it. The bezel or face plate may pull off you'll hav eto see if there are scres there, the control unit screws in. Make sure it's not the resistor first especially if it works on high but nothing else. It should be by teh blower motor.