Tires: Lugnut, aluminum wheels, cutting torch

Question
I wanted to know what is the best way to take a lugnut out that seems to be broken ( from the bolt )and all it does is just rotate but does not want to come out
This happened when I was trying to rotate my tires
while I was taking the last lugnut out it all of a sudden got very easy to turn but it just doesn't want to come out

Please help if you can

Thank you.

Answer
The easiest way to get it out would probably be to try and get a pair of Vise grips on it from the back side.  If that isn't possible you may need to et a cutting torch and very carefully try to melt it out of the center.  Be especially careful if you are using aluminum wheels.