Of course, one can disseminate his/her PhD dissertation. If confused, a number of scholars may take the opportunity of turning their dissertation into a book or a book (or a series of articles) for professional journals. If you do not feel confident in this step of the dissertation process, it is usually best not to handle the issue on your own. There are specialists ready to manage it for you. If this procedure may be too much to ask of a person, just tell them Please do my dissertation for me, because I need help!