After uploading, you can always update your book (including the files, metadata, and the prices) and save the changes. There is no need to withdraw the book or upload an 'updated' version.
You can make any changes right after sending your book to stores as well when it is shown as Under review with "Stop review & edit book" button.
Once your book has passed processing, it will be sent to stores and shown as Published. Your book will be reassigned to you, and you’ll be able to edit it again.
Just click the "View and edit" button to edit the book, then press "Edit" again to unlock your book page. You'll be able to change anything (price, title, description, etc.), or even upload an updated version of your book. (To upload a new file, simply drag & drop it in the file field.) You can always download your already uploaded files with the little download arrow in the top right corner.
You can change everything without withdrawing the book, even upload a new file. (If you are running into errors, please check this article.) The only detail you cannot change after publication is the ISBN, we are unable to add these later on. Your changes will be sent to stores once you press "Update" and take place within a few hours or days.