Basically, there's two ways I know about (well three if you count a trade exception).
The first is that you can resign existing players on your team over the cap, so Pierce could resign, and then they would then be 12.05M over.
The second way is the mid level exception, which is 5.00M, and that means each team has 5 million to spend if they're over the cap. I'm pretty sure this is somehow related to Larry Bird, I think it use to be called the Bird exception. There also might be other exceptions, I think I read about them on NBA.com, I'm not quite sure about them. Correct me if I'm wrong guys.
