changing spark plugs

There is a screw that takes off the thingy that sits on top of the spark plug. Be sure to buy new boots that cover the plugs as well as the spark plugs. Autozone

Where are the spark plugs located on a 2001 town car

The spark plugs are located directly under the individual coil paacks. There are 8. Use a 7MM socket and a magnet to retrieve the bolts, gently twist out the coil pack. If it leaves the boot behind, no worries, just twist and pull gently. Blow out the debris in each spark plug hole with compressed air or risk trashing your engine. 5/8" spark plug socket ( I use a double swivel with 9" extension and a swivel handled ratchet). Don't use power tools on aluminum heads. Use a very small amount of Anti-seize on the spark plug threads. Gap the plugs, use a short piece of vacuum hose to start threading the spark plugs. Also, use Dielectric Grease (about a pea-sized glob) in the end of each spark plug boot. In all of my years with the 4.6L (since 1999) i have rarely replaced a spark plug boot unless it was damaged.