If it is like the Deville models, you should have a special tool that will remove the center bolt. The owners manual will have a picture of this tool. Use the flat edge of the tool to remove the center decoration, and then use the rounded end to remove the center bolt. The hub cap will then basically fall off.
Simple... You remove the wheel from the car and punch out the center cap from the backside of the wheel.
pop off center cap loosen nut with toll located in glove compartment wheel cover should come right off
Screwdriver
Remove the center cap, washers and C-clip and the wheel should slide off.
You must remove the wheel because there are scews that hold it onto the inside of the wheel.
The only way to remove it without damaging it is to remove the wheel and tap cap off from the inside.
The centre cap has the same function as most hubcaps. It is mainly for aesthetics and to protect parts of the wheel from dust, debris and water (to a point).
If you are asking about the center "Hub-Cap" on the stock wheels, and of their removal, you have to remove the wheel from the car first. On the inside of the wheel, there are I think three 5/16" head screws that screw through the wheel into the plastic hub cap. Once you remove these screws, the cap is free from securement and will simply fall off.
Remove the grease cap in the wheel center. Then remove the cotter pin, and finally the nut. The brake drum should slide off. Remove the grease cap in the wheel center. Then remove the cotter pin, and finally the nut. The brake drum should slide off.
HAVE YOU EVEN TRIED? JUST REMOVE THE TIRE FROM THE HUB, TAKE A SCREWDRIVER AND PUSH IT OUT. STUPID QUESTION
Use the lug wrench. If the car has wire wheel caps, you may have to use the adapter tool to remove the center cap and unscrew the cap from the hub.
To remove the standard wheel cover stick the pry end of the lug wrench behind the outer edge of the wheel cover and simply pry it off. If your car has the wire wheel covers use the special wrench that comes with them to pry the center cap off then remove the retainer nut to remove the wire wheel cover.