The lug nuts on your wheels keep the rims secured to the car, making sure you don't lose a wheel while driving down the road. Like any nut, though, you could strip the outside hex shape, rounding off the lug to the point where it seems impossible to remove. You can probably get the lug nut off without resorting to a professional mechanic, but you'll have to get creative to do so.
Determine what size lug nut is on your wheels using the 1/2-inch socket set, using one of the non-stripped lugs on the wheel. Once you know the size, choose a socket that is one size smaller and slide it over the rounded wheel lug. If it fits, go another size smaller until you find one that just barely doesn't fit on the lug. Make sure, once you've determined what size to use, that you pick a socket that you won't reuse, because this socket is bound to get damaged in the process of removing your stripped lug nut.
Hold the socket over the rounded-off lug nut and push it over the lug nut as far as it will go. Then hold it by the sides and hammer it in place using the 5-lb. sledgehammer. Pound the socket all the way onto the lug until it's solidly on there and won't twist in any direction.
Put the 1/2-inch breaker bar onto the socket and turn it counterclockwise to release the wheel lug. Then discard the old lug and the socket if it is damaged.
