Kaltura's Collaboration tab allows three options: Change Media Owner, Add Co-editing, and Add Co-publishing. After uploading a video, you can give one or several other people the ability to edit the video (Co-editing). You can also grant certain individuals the ability to publish the video on other course sites (Co-publishing). Or, if you would like to give up ownership of a video, you can now do so with the Change Media Owner option.
You can also this video tutorial from Kaltura Support:
Once you have added another user as a collaborator, send them our guide detailing how to edit or publish your media.