are directly above the spark plugs, you need to pull them off the plugs to remove the plugs so you can't miss them
You may as well check the spark plugs whilst you are there to see if they give any clue as to which cylinder may be the problem....if indeed it is the problem! Check the gap and condition obviously!
Another 'quick' check is to pull each coil
off (or at least unplug the electrical connection to the coil
) one at a time to see if there is any change to the engine! If you pull a good one then you should get a miss fire, if you pull a bad one then you'll probably notice no change at all to the engine note/firing! Don't leave anything unplugged whilst the engines running for too long as you may cause damage