In WCMS 3, you can replace files. Replacing files means the links to files on webpages will automatically update with the link to the new file. This way you will not have to manually update every link on a site that links to the replaced file.
From the administration bar, select Workbench, and then select My Dashboard.
Navigate to Media.
Select the drop-down arrow next to File, then select Manage.
Locate the file you want to replace by searching for it by the file name. You can also filter by Published status or navigate between media types/search all media using the Type drop-down menu.
Select Edit next to the file you want to replace under Operations.
Select Remove.
There are three different ways to add a new file:
Reference existing: Select a file that has already been uploaded to your site from the list on this tab. This prevents numerous copies of the same file from being uploaded and stored.
Upload: Find a file using the file browser to upload from your computer.
Remote URL: Enter the remote URL of the file you would like to reference.
You can edit the Name of the file if applicable. Be sure the name of the file matches the content of the file you are replacing.
Select Save.