why do people insisnt on giving bad advice??? USE ONLY THE OIL THE TRUCK CALLS FOR. The info is on the sticker on the left side on the radiator support and it says use ONLY 5w20. Don't be a TOOL and use anything else or you will starve your bearings and crap out the engines. If you are going to do something, do it correctly or why waste your time fixing something preventable?
Before you try and take a spark plug out, the engine must be stone cold prior to doing work on it. The reason for this is the different cooling rates of the aluminum heads and the steel spark plugs, you will strip the threads and make a mess out of your heads, so dont even move it before taking the plugs out. You will need to remove the plastic intake and tubing to get access. A 6" extension and a swivel will come in handy. Disconnecting the fuel rail from the injectors will make removing the COPs a lot easier. Antiseize the plug threads and use dielectric grease inside the COPs. Do not worry about replacing the COPs until you have too, unless you have money to blow. A Haynes manual does a pretty good job giving you a step by step as well.