Lug nut caps are usually fitted over the tire rim lug nuts to make the rim look fancy. They need to be removed to access the lug nuts. Some lug nut caps are part of the hub caps and are removed as a whole unit. There are also single caps that fit over each individual lug nut. Lug nut caps come in various sizes and will require a certain size socket depending on the vehicle.
Locate the lug nut caps on the tire rim.
Unscrew each lug nut cap using a rotary tool such as a ratchet. Loosen all the caps for a hub cap unit and then remove the whole unit at once.
Pull off the lug nut caps. Some caps are not threaded and can be pulled off with force, as can some hub cap units. These kinds of lug nut caps are usually manufactured as a very tight fit to the lug nuts and might require some effort to get them off.