How To Change Bookid Root

[djkrob5]

trying to import songs from a cd that were once there as kma but have since been deleted...when i try to "import tracks" it tells me the bookid you have selected is already in use...please select or type another bookid...and when i try to delete the bookid or rewrite it in the book id box it won't let me...i can put the curser in the box but can't change the number that's in there by backspacing of deleting...and the next button is not highlighted to b pushed...how do i change it