Replaced mine today thanks to this walkthrough. I never found any particular part difficult, it was just time consuming in general. Took me probably 2.5 hours but it's not like I was in a rush.
I bought this spark plug socket which made getting the plugs out pretty easy, even the driver's side rear.
As far as putting the plugs back in, I did have to get them started with a normal spark plug socket and a drill bit adapter.