You can modify or otherwise customize the slides by opening and editing them in the appropriate application. You must, however, retain the denotation of the original source of the material; it is illegal to pass it off as your own. You may indicate that a document was adapted from the workbook, written by Lisa J. Downs and copyrighted and published by the American Society for Training & Development. The files will open as "Read Only," so before you adapt them, you will need to save them onto your hard drive under a different file name.