So i am installing my new rims and tires tonight and the back 2 went off without a hitch but when i got to the front to the middle piece for my new rims popped out because of a silver piece coming out of the hub. i tried unscrewing it unsuccessfully i was wondering if someone could tell me what is under the cap and if it is removable because if not i am going to have to paint it black to match the rims and i would like to avoid that if possible considering how much i just spent on these.