Remove files from Media Libraries
To remove a single file from a Media Library, first navigate to the Media Library. Then, click the Media options button for the video, audio, or image you want to remove from the Media Library.
Select "Settings" from the dropdown menu.
At the top-left of the Media Info page, click the "Remove from Media Library" link.
You'll be asked to verify your choice. Click "Remove" to proceed.
If you have copied a file to multiple Media Libraries, removing it from a single library will leave the remaining copies intact.
Also, you can check the "Delete this media from all Media Libraries" box to simultaneously delete all copies of a file.