So, the front three were some of the easiest plugs to ever change.... Whats up with the back three? Does anyone have some advice or assistance with how to change these?

 

This works:
Remove the coils like you did on the fronts. Pull off the rubber weatherstrip seal along the back of the engine compartment at the cowl to give yourself a little more room. It goes back on easily.
Then set up your wrench with the spark plug socket, a short extension, a u-joint, another short extension and the ratchet. "Roll" the socket and extensions down into the hole from behind the engine, There should be just enough room to swing the wrench between the valve cover and the cowl.
Other tips:
Don't gap platinum plugs. They come pre-gapped and you can scratch off the platinum by gapping them.
If the plug is not un-threading easily, run it back in to break off any deposits on the threads. You do NOT want to drag a hard deposit out through the threads and risk buggering them up.
Use a piece of rubber tubing or hose to start the threads in the hole. If it's not going in easily this will prevent cross threading.
Use antisieze on the threads of the new plugs.