Transfer Ownership of a Media Library
If you transfer ownership of a Media Library to another user, you will no longer have owner privileges for that library. you will remain an authorized user and administrator of the Media Library, but the new owner will be able to revoke those privileges if desired.
In order to transfer ownership of a library, navigate to the Media Library settings page (Click the name of the library in the upper-left and select "Settings" from the dropdown menu).
In the upper-left of the Media Info page, you’ll click "Change" on the line that lists the library's current owner.
You'll use the search box to find the user you want to grant ownership of the media file. You can only transfer ownership to another user, not to a group.
Click the name of the User to whom you want to transfer ownership. Their name will turn green, and a popup will ask you to verify your choice.
Finally, you'll see a message verifying the successful completion of the transfer.