Open the required file in viewer on which a new revision needs to be uploaded.
Next, follow the steps for navigating to File Viewer More Options.
In the 'More Options' menu, select 'New Revision' option (under 'New' category) to upload revision of selected file.
Click here for detailed help on uploading a file revision - refer steps 4 and 5.
Next Article: Start a Workflow on a File open in Viewer