Removing unused styles in Word 2010 docs

HI
Do anyone know some exact method of removing any unused styles in a Word 2010 document as well as I am concerned to this as I don’t wish to do that so one by one in the Styles task pane? Doing it manually by stepping from side to side all of the styles one by one, and then checking whether each style is in use or not as well as subsequently deleting the styles I don't require. So guys can you find out some means to take away all styles that are not used in a document?