How do I replace the blow motor resistor in a 2002 pontiac Bonneville and where is it located on the vehicle?

Easiest of all manufacturers to change .. it should be under the passengers side mat toward the glove box. You may need to do contortions but once your in position you have done the most dificult part of the job .. The module is less than $30 bucks on Ebay

Just changed that part on my 03 ..once the glove box is out,it is still tricky to spot that module...it is immediately behind another black box which has 2 screws on the left to remove (you will need open end wrench for 1 of them) then once that box is dropped down slightly you will see the module mounted to fan shroud box..1 screw should remove it & a plug in wiring harness