Upload A New Version Of A Document
To upload a new version of an existing document, from the document details page, click the Upload New Version button at the top (This can also be done via the More menu (icon with 3 stacked dots) found to the right of the document in the list view). In the upload a new version window, browse for the replacement document on your computer. Double click the file to select it. Click Continue.
You have the option on this page to Keep or Delete the prior version. If you Keep the prior version, Documents will start tracking multiple versions of the file, assigning sequential version numbers. A file with multiple saved versions will display the current version of the file in the folder view, and will list all versions in the Document Comments page.