Team Projects unlock sequence and media clips^

I tried out the Team Project feature and invited someone to join the project. Unfortunately relinking via media manager to an exact copy of the media didnt work and we did fiddle with the relink panel as it was prompted on startup unfortunately. Now the sequence PLUS ALL my media files have the status "user x is editin" and are locked. I dont want the other user to be part of the team project anymore. How can I reset user rights and regain control of my sequence and all media clips?