Once you have the coil packs out of the way you are ready to remove the spark plugs. What I found to be the easiest for all four cylinders is to slide the 5/8 inch spark plug socket onto the spark plug first, and then the knuckle extention, the 12in extension and then the 3/8 ratchet. The spark plugs are deep so your gonna be thinking these things are never gonna get out. Be patient with the rears because you are at a very odd angle. The closer you can get to perpendicular with the cylinder the better you will be. Here is a side by side of the old and the new (Pic 1).
Before you start to install the new plugs when all the old ones are out, check the gaps between the two. I know the spark plugs come pregapped, but you don't wanna find out after you have them in that the gap is too large and your misfiring. Be careful when you check the gap to not damage the electrode (it is very delicate).