Don't bother. Unless you're experiencing some fault code that is directly related to the ignition system (in which case, it might be better to have a dealer do the work) there is no reason to change the plugs. Search for other threads on the subject, I think you will find few posts that say it was a worthwhile expenditure of time or money. I replaced my plugs at 75,000 miles. The old plugs looked like the new, only in a slight light brown finish.
If you decide to continue, it's not the easiest job to do. Remove the engine cover, remove the plastic coil cover. Each plug has it's own coil, disconnect the electrical connector and remove the single bolt. On the left bank, you will likely need to remove the heat shield and on the right bank you will need to remove the breather valve. Each plug is deep down in the hole. The front plugs are easier the rear plugs need multiple socket extensions to get just the right amount of reach. Too short and you won't reach the socket. Too long and the extension won't fit. Before you start, have on hand a selection of various length socket extensions and flex joints
