My 2002 Trailblazer with 117,000 has a burned out headlight. The manual says take it to the dealer. Any tips on doing it myself?
These bulbs can be a real pain to change because of several factors including a plastic shield and the danger of breaking the grille. To make matters worse Chevy decided to put a few fake screws in the mix. The best bet would be to take it to the dealer or to a good mechanic that has experience with replacing these headlight bulbs. The bulbs are a no-brainer to replace but getting to them is another matter entirely. The owners manual does not address changing the bulbs at all. There is a shortcut but it could lead to broken components so I won’t mention it here.
Take it to a mechanic or independent body shop. Avoid the dealer; you will save money and time!
Wow, they must have made some big changes from '02 to '04 because they are really easy to replace on mine. Right behind the lamp is a black rubber plug. Pull the plug and there’s the connector. Twist and pull to remove. I’m surprised it is so difficult on the '02.
They must have. I had a 2002 Envoy and the lights were just as difficult to change. The owners manual even referenced taking the vehicle to the dealer to have the bulbs changed. My model even had the “run flat” tires. I thought it was a great thing until they wore out around the 10K mark. That was only 9 months into ownership. I’m glad GM wised up on the bulbs.
My o3 TrailBlazeris the same setup as TT, piece of pie 
I dread having to change out the bulbs of the car I’m getting. It requires one to go in from the wheel well to even reach the headlamp, even shows how to do it in the manual(I have a PDF file of it)
My daughter’s 2002 Civic was a nightmare to chenge.
My tC is a piece of cake.
IMHO there is no credible reason they have to make headlight bulbs so difficult to replace. But the often do.
I believe you must pull the grille or grille bar off to access the headlamps.
I sure hope not, sure there are no rubber plugs? After looking on the net it appears 02 is different, but there are some tabs, hard to see, that you unlock to pull out the whole light assembly, I had to do that on a GMC truck, hold on I’ll try to find the info.
“Open the hood, at the top of the lamp assembly are two inverted “L” shaped pins. Rotate each pin 90 degrees and pull straight up. This will allow you to pull the headlight assembly forward. There is a release on the bulb socket, depress this and rotate the socket counter clockwise. When replaceing the bulb, handle it with a clean cloth or gloves. The oil in your skin will cause the bulb to burn out faster, making you go through this process again. hope this helps.” stolen from wiki answers