While trying to change my tire i have taken off all the lugs and need only to put on the replacement tire. I have had trouble taking off the old wheel though? Does anybody know what i need to do, or am i just not pulling hard enough? Because i pulled with as much force as i wanted to put on my car and it seemed like the old wheel was still attached. I took off all 5 lugs but there does seem to be a center metal piece that obviously fits into the wheel, but on that piece there is another bollt type pattern, is there something there that i need to loosen? Any advice would be appreciated, thanks.