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Just to add my two cents to the sound advice already given...
There are 8 coils that are installed on top of the 8 spark plugs on this vehicle. They are not installed at an angle on the sides of the cylinder heads, but rather go straight down into the heads on either side of the intake manifold.
You really want to get informed when trying to replace plugs on one of these engines. There are a few things that are important...such as making sure to let the engine cool before trying to extract the spark plug, as you might strip the threads otherwise, or break a plug (see the question 3 down from this one!!!). You should always replace the rubber coil boots when changing the plugs. And you should torque the new plugs down to the appropriate specification.
This is why investing in a good manual is very much worth it...what the other guys are trying to say also. Good luck.
Good info on the need to be informed. I'd like to add something here. These plugs often don't want to come out of the head, even if the motor cooled overnight before extraction. I highly recommend getting the engine hot, taking all 8 coils out, back off each plug 1/4 to 1/2 turn, then spraying a very high powered penetrant down tubes, let soak over night. in the morning tighten the plugs before you remove them. This process is actually recommended by Ford for many of these triton engines. By the way, wd-40 is not a high powered penetrant.
It is very common to damage these cylinder heads during spark plug replacement, or shortly after replacement. head repairs in vehicle are not always successful. Head repair or replacement off the vehicle is very expensive.
I would definetely have the dealer or a reputible shop do the spark plugs on this vehicle as they are so easy to break off, and there is a special tool out there for extracting them that the dealer has.
Great answers Gents, I definitely agree with all of you. No disrespect for anyones mechanical skills, but if someone has to ask where are the spark plugs located - he/she better has the manual and do lots of research on this motor. I'd take Woodward Auto's suggestion to take it to the dealer.