One of the smartest and most cost-effective ways to improve the audio performance of your 2002 Chevrolet Trailblazer is to replace the existing factory speakers. Aftermarket car speakers usually offer much better performance than what you’ll experience with the factory-installed models. If you plan on doing the job yourself, you’ll need to invest some time, but there are no technical issues you can’t handle and the tools needed are readily available and simple ones.
Items you will need: Phillips screwdriver, 9/32-inch socket and ratchet, Panel tool, Torx T9 driver
Front Door Speakers
Remove the single Phillips screw from the back side of the door release trim.