The debut of the TrailBlazer in 2002 marked the end of the road for the four-door Blazer. The TrailBlazer lasted eight years, and from 2007 through 2009, it was available in an SS trim with a 391-horsepower, V-8 engine. Replacing the low-beam headlight in your 2002 TrailBlazer requires that you remove the front grille and the headlight assembly to gain access to the bulb.
Open the hood and use a flat-head screwdriver to pry the grille-retaining clips from the body -- there are 11 clips that hold it in place. Pull the grille from the TrailBlazer and set it aside. Pull upward on the two retaining tabs on the top, rear of the headlight assembly to release it, and pull the headlight assembly away from its bed to gain access to its wiring harnesses.
Disconnect the wiring harnesses from the headlight assembly by pressing their respective unlocking buttons and pulling them from the assembly. Remove the side marker and turn signal sockets from the headlight assembly by rotating them counterclockwise and pulling them out.
Twist the headlight bulb counterclockwise to unlock it, and pull it from the headlight assembly and unplug its harness.
Plug the wiring harness into the new No. 9006 headlight bulb and insert the bulb into the headlight assembly. Twist the headlight bulb clockwise to lock it into place.
Reinstall the side marker and turn signal sockets into the headlight assembly, and twist them clockwise to lock them into place. Plug the wiring harnesses into their respective receptacles in the headlight assembly. Align the headlight assembly locating pins with their holes, and guide the headlight into its bed. Press the retaining tabs on the headlight assembly downward to lock it in place.
Line up the retaining clips on the rear of the grille with their slots in the front of the TrailBlazer. Press the grille firmly into place to snap all of the retaining clips into place. Close the hood.
