They are easy to replace, and no need for the expensive plugs. Just stick with the autolite 5143 for less than $3 a plug. That is what I always ran, even with nitrous and the Xcharger.
You will be working blind for the most part because of the angle and such. Remove and replace one at a time so you don't mix up the spark plug wires. And with 110,000 miles you may want to replace the wires as well; again no need for the expensive ones, I used the set from O'Reilly's with no problems on my 2006 with the Xcharger (and put 203,000 miles on that car).
When you go to pull the spark plug wires grab the boot and pull, not the wire.
When you put the new plug in use some anti-sieze on the threads. Get the plug started with your hands. I used to insert the plug into the plug socket so that the rubber could hold it in place. And then reach down and start it in the hole. You want to get it started by hand so you don't cross thread it in the aluminum head. If you try to start it and use the socket wrench to do so you run a big risk of cross threading it. Once it is in a couple of turns (should be easy to turn) then you can use your socket wrench to seat it in place.
When you put the spark plug wire make sure you hear it "click" into place. It should be snug.
The last plug on the passenger side was always the problem I thought. It angles back toward the firewall so not a lot of room and you can't see anything. The others aren't too bad.
As I recall on the passenger side you have to undo one bolt near the alternator to release the plug wire and access it. (Been a long time so can't remember for sure now) I also don't remember the stock plug gap but it should be in the owner manual.