OK folks, we have a few options to mass delete content and libraries within salesforce.com. This is a task Salesforce Admins face constantly when you use Salesforce CRM Content and Libraries. There are 2 options below. You can pick the easier one.
Content Documents or Files can be deleted using Data Loader.
Delete Libraries using Data Loader and the same general steps below but export and delete against the ContentWorkspace object instead or ContentDocument. Alternatively manually delete libraries via the user interface.
Note: Best practice is to perform a Data Export for backup prior to deleting records within your organization.
1. Log into Data Loader
2. Select ‘Export’
3. Check Show all Salesforce objects” and select Content (ContentDocument) object
Note: Deleting a ContentDocument will automatically delete all related ContentVersion records.
4. Select Id and any other desired fields& and follow the prompts to complete your export.
Reference: Exporting Data
5. Review the resulting CSV file to verify the Content to be deleted
6. Return to Data Loader, and click Delete
7. Follow the prompts to select the CSV file you reviewed in step 5 and delete the Content For more information, see Inserting, Updating, or Deleting Data Using Data Loader
Once the content is deleted, navigate to the Library in your org to delete it.