Yes you can. Here are the steps on how to edit an Audiobook
1. Find an audio-editing software which has the editing features you want, and download it. Audacity and Adobe Audition are two popular choices (see links in Resources).
2. Transfer the unedited reading of your audio book to your computer's hard drive (if necessary).
3. Open your audiobook file from inside your audio-editing software. Many audio-editing software programs come with automatic file conversion capability so that when an audio file is opened, it's automatically converted to a medium that the program can work with. If your software doesn't have this capability, you'll also need to download audio converting software. Choose software capable of converting the file type of your original recording to a file type supported by your editing software.
4. Play back and listen to the reading of your audiobook. Stop the playback in areas you'll need to edit, such as a word or phrase you stumbled upon, long pauses that should be shorter, extraneous talking, bodily noises or the sound of paper rustling. You can insert rereads of certain passages, silence or reduce the volume of loud breathing and background noise.
5. Save the reading of each chapter of the book as an independent file. Saving the entire book as one file will make indexing the book much more difficult. If the editing software you're using has a multiple track feature, you can copy and paste each reading of a chapter to its own track and save each track as its own file. If your editing software does not come with a multiple track feature, you'll have to keep a master copy of your audio reading then create a copy of this master. Open the copy of your audiobook and delete the reading of all but one chapter of the book, then save that one chapter. Keep repeating this pattern until all of your chapters have their own independent file.
6. Listen to the edited reading of each audiobook chapter all the way through to make sure that you've performed all the needed adjustments.
Resources: NPR: The Art of Recording an Audio Book (video)
Free Download of Audacity Sound Recording and Editing Software Download Free Trial of Adobe Audition Audio Editing Software
Hope this information helps!