You have to take off the plastic intake cover there are a few screws holding it on. This will expose the front 4 plugs. To get at the rear 4 you will need to remove the spark plug coil packs, there are 4 bolds on this assembly I believe, then you can get at the back 4 plugs. Some of these may also need to be accessed from the bottom of the car, if you have big hands.
Up Your Butt And Around The Corner! >.<
How to Replace spark plugs on 2004 cadillac deville Sls with 4.6 v8 engine
How can I change the wiring and spark plugs on my 1996 Cadillac Sedan Deville Concours?
where are the sparkplugs on a 2002 cadillac deville and how to change them
I don't know when Cadillac started doing this, but they eliminated the coil packs and have since been using coil on spark plug coils. They are directly over the plugs on the engine. You have to remove 4 or 5 bolts to access them.
Pull wire off the spark plug
Recommended change is 100,000 miles
the gap specifications is 50 on a 2002 Cadillac Seville
Spark plugs are easy to change. One disconnects the batter and spark plug cables, and removes the old spark plugs. Next a person puts in the new spark plugs, then reconnects spark plug cables and the battery.
If you are facing the engine from the front bumper, they are on the back side of the engine in the same position as those on the front.
2000 Cadillac Seville SLS 4.6L SFI DOHC 8cylThe Spark Plug Gap.050 (In thousandths of an inch)
Disconnect the battery, remove the spark plug cables and boots, and remove the old spark plugs. Dispose of the old spark plugs, put in the new spark plugs, attach the spark plug cables and boots, and connect the battery.