To upload a New Version of a Resource, first go to the existing resource and click on Edit/New Version in the dropdown action menu. Here you can browse your desktop for a new version and add a Version Comment if required/mandatory. Once complete select Save. The new version will replace the previous one in the resource folder.
Once uploaded the resource will have a V2 against the file name.
Users with access to the Version Control module will still be able to access previous versions in the Info box of the main resource under the Version tab.
Note that the Version Control tool must be activated on your platform to use that functionality.