Two of those chromed nuts are not "fake", and these two screw onto the extra threads left over on the ends of the regular wheel lug threaded shafts. These two chromed real nuts are opposite each other on the circle of the eight chromed nuts (hence two of them are real nuts, and six of them are fake nuts). The six chromed fake nuts on the circle are permanently part of the chrome wheel cover and cannot be turned and unscrewed.
The two chromed real nuts are the ones with two small opposing indentations on two opposing flat spots on the base of the each real nut - where the wrench to removed them fits. Look carefully for these indentations and then just unscrew these two real chrome nuts and the chrome wheel cover can be removed so as to better reach the valve stems.
Our Class C came equipped with a wrench that fits the two real chromed nuts - for unsrewing the two chromed real nuts with the indentations and removing the chrome wheel covers on all four wheels.