Dennis @ PerfectForms
Create a backdoor access for yourself. Add a hidden button to the form. When the form opens use a simple branch. If the User first name = your name use a set state to make that button Normal. Make sure to make it hidden for the false branch. When the button is pressed use a Set Next Stage object (to your closed stage) and a Submit object. Save your changes, publish the form, and map the old instances to the new version: /Documentation/manual/html/?fl_mapping_form_instances_to_anot.htm.
Open the subject instances from the dashboard and click your button.