Check yellowpage under wild life control and find a company that can come and remove it. I had it done last year. Costs over $100. I heard that you can remove it yourself by applying a kind of spray (buy something from HomeDepot).
It's true. when I hired a professional to have it removed last year, the service came with a warranty that they would remove it free of charge if the bees are back at the same place the following year. They spray something on the surface to make it an undesireable place for bees, but you never know. This year I've noticed the bees are flying around that spot again and again for couple of weeks.