The 02-09 "How-To" and DIY Section
http://www.youtube.com/watch?v=IhBebL0JeAs
A quick simple explanation of how to change spark plugs in a 2005 or later Chevrolet Trailblazer.
You don't need to be super handy to do this, and it will save you money!
* The only slightly difficult part is the removing the wire harness to get at...