I only replaced my plugs, but it is a good Idea to do all the parts. It was fairly straight forward, as noted, I had trouble with the 1 plug nearest to the passanger seat due to the shortness of the plug wire. The drivers side took like 10 or 15 minutes.
as I remember, just take off the two allen screws on each plug(most done by touch, not sight), take out the plug and reverse. Pretty simple.
Hint, don't start with the hard plug. Start with the one closest to the passenger rear of the car. You will get a hang of it by the time you get to the tough one.
Then the other side is a breeze!!