Location of spark plug

Engine Mechanical problem
2003 Chevy Trailblazer 6 cyl Four Wheel Drive Automatic

Im working on my friends trailblazer what do I take off to get to the spark plugs?

Funny you ask that; just did mine today. Attempted to do it last year and couldn't find out where they were.

You have to take off the cover that sits directly on top of the cylinder head. It's connected to the air intake on the left side and the carb on the right side; there are only two bolts. Underneath, you will have an additional six covers, not sure what they're called, that connect to the spark plugs. They each have one bolt in them. Remove each one to get to each spark plug. You'll need about a 6" extension to get to each plug.

Pretty simple, should take less than an hour.