Try importing the book into Calibre (which is a free download from
http://calibre-ebook.com/). Assuming you can do that, right-click on the title, and select Edit meta information, and then Edit metadata individually.
You'll see a window where you can edit the author's name, the title, the publisher, and a few other things.
Note that the above applies to Calibre 0.6. In other versions, the method might be slightly different, but the overall approach will be the same.