Went to change spark plugs as well since they're the originals with 92k miles on them now.
Driver side 1, 3, 5, 7 was easy enough from the top when I did that a little while ago.
Tackled the passenger side 2, 4, 6, 8 today and since it was a pain I took the wheel off and the fender liner off.
Number 6 was a pain in the ass coming out, turns out whatever moron put the plug in at chevy, cross-threaded it.
New plug wouldn't go in without cross threading.
Had to really work at cleaning and fixing (chasing) the threads to get a new plug back in.