Delete old Toolbar Addon in Firefox 25.0.1

Using FF 25.0.1 and NIS stand-alone:  I have an old version of Norton Toolbar (about 2 months old) that is not compatible with FF 25 (or 25.0.1), and is disabled by FF.  There is no option to remove it.  NIS Stand-Alone says to turn on addon settings - I do, and the old bar is grayed out but there is no DISABLE or REMOVE button on the toolbar.

 

How do I get rid of it so I can install a new version of the toolbar??