Navigate to the Canvas course in which you want to remove the videos from the Canvas > Mediasite section.
Click on My Mediasite button in your canvas course, and then click Authorize
Click on the Search Icon, and enter the course ID, semester or title of the video and press Enter
For example: MEDE.8810 Spring 2019
Select a video from the search results
In the Visibility section, click on the dropdown box and change the visibility from Viewable to Private
NOTE: Changes are saved immediately