Yes. This is very easy if you have converted the updated copy to EPUB… then follow the steps in the screenshots below
Sign in to the account you uploaded the book with… Go to Publish Books – My Publications
Click on the Pencil Icon in front of the book you would like to Edit… A new page like the image below will open… Click On the X icon to delete the old book. You might get a warning, ignore it and don’t close the page… 

You might get a warning, ignore it and don’t close the page…  
Click on the UPLOAD EPUB option to upload your new copy

After it’s been uploaded… Click On REPUBLISH