Book details and covers
Open Books and select the book whose details you want to change. Use its details/edit controls for title, description, book type and other available metadata. Select the cover through the existing image/media controls. Check the book title before saving so that edits apply to the intended book.
A cover is separate from chapter images and a Full Page Image manuscript page. Preview your book to check which image appears as the cover. Editing metadata does not publish your book or automatically submit it to a retailer. Keep a copy of important original artwork.