The spark plugs are situated at the center of every cylinder head. In most instances, when changing spark plugs, there are some tools that must be used including a spark plug socket which is attached to ratchet, extensions for different lengths and a feeler gauge to check the gap on the spark plug. These engines have aluminum cylinder heads thus a torque wrench must be employed while tightening the spark plugs. The best way to change out spark plugs is to buy new ones prior, check gaps then replace each plug one by one. Do not forget when buying new sparks plugs to obtain the correct ones for your engine's model number. Make sure that engine has cooled down completely before you start removing any of its plugs. Meanwhile, during this time of cooling down all new spark plugs will be examined especially if they have defects and you can check their gaps as well . You can know whether gap is good by inserting proper thickness gage between electrodes located at tip of plug . However, cover the fender so as not to scratch it . Take off ignition coil cover and engine cover . Remove ignition coils. Use compressed air if available to blow away dirt or other foreign matter from around where the spark plug enters into the cylinder head combustion chamber area. Put the socket on top of a plug and remove it from an engine through turning in counter clockwise direction . To get a general idea about how an engine runs compare these two items using chart . Apply little quantity of antiseize lubricant compound on threads of Spark Plug. Insert one of new plugs up into hole until it stops turning with fingers anymore, then use torque wrench for tightening or ratchet wrench in doing so . Twist coil onto end of new Spark Plug until it is seated tightly on it. Fasten mounting bolts firmly in place Repeat above procedure for other remaining spark plugs.