>Does anyone know how to move a class from one library to another without retaining any links to the original library?

You can copy the class using the Class browser: open the old and the new libraries each in their own instance of the class browser. Highlight the class to be copied and then drag the icon in the upperleft corner to the other CB instance. Hold the CTRL key if you want to copy instead of move.

If the class was subclassed from a class in the first library, the link will still hold. To change the parent class, right-click on the new class in the CB and choose redefine to choose a new parent class.