How do you replace a blower motor resistor on 2002 Chevy Malibu?

It is located under the glove box, way in the back of the passenger foot area. You'll need to remove 2 screws with a 7mm socket, and remove the plastic cover that covers the blower motor and another component box that I think controls the passenger airbag. After removing the plastic cover you'll need to side that passenger airbag module to the right so it pop off its mounting bracket and move it out of the way. That'll give a better veiw of the blower motor. I highly recommend you also remove the blower motor itself because the Blower Motor Resistor is located behind it. I think you'll need a 5mm or 5.5mm socket to remove the 3 screws that hold in place the blower motor and 2 more screws for the Blower Motor Resistor... It's a cramped location to work in but if you have all the tools and enough lighting then it shouldn't take more than 30-60 minutes to do. The Blower Motor Resistor costs about $19-$25. I bought mine from http://www.advanceautoparts.com . Good Luck!
also use a 1/4" universal joint and a 3" extension on a 5.5 mm socket to get to the farthest screw. trust me it will make alot easier