You can access the Settings for any asset by clicking the media option icon to the right of the asset title, then clicking "Settings."
From the Media Settings window, as the asset owner or a Media Library admin, you'll be able to edit the title and description, choose a custom video thumbnail, add closed caption files to videos, add Tags, change Visibility, View Analytics, Remove (or Replace) the file from the Media Library, create a clip, and transfer ownership.
The Media Settings view will look different to users with different permissions (admin/owner/user/contributor). Using the following link to learn more about Warpwire Permissions.
Just type in the Title and/or Description text boxes to edit them. Click "Save Changes" when you're finished.