You can edit an element without having ownership of the workset it belongs to. To do this, you borrow the element from the workset.
The borrowing process is automatic unless another user is editing the element or the workset it belongs to. If this occurs, you can submit a request to borrow the element. When your request is granted, you can edit the element. If changes were made to the element, you are prompted to reload the latest changes from the central model before you can edit the element.