spark plugs in 4200 i6

Anyone change out plugs in their trailblazer inline 6 ??? I haven't but want to attempt it . 55,000 miles. I heard they are good for 100,000 miles... but how is it done and if I need to or not. As you can tell,I haven't the need to get under the hood since we got it new in 03. Other then washer flud and oil changes.Havent tackled the plugs yet. I got a 01 f-150 I want to change them also. These new vehicles make doing plugs a mess!! What ever happened to the old easy access and room!!lol

Take the air intake assy off, this exposes the coil packs, remove one at a time and replace the plugs, stay with AC 41-103 at .050 gap, do this engine cold of course. Forget the F-150, I swore I wouldn't do them again, they really have to be cold and even then some threads have been pulling out of the heads 4.6/5.4.