How to change the status on a film?

You need to add a Production Status through the standard update system. Start by clicking on the Edit page button. Production Status is in the Other Data group (second group from the bottom). Although the Status can only be seen on the Pro version of the site, it can be updated from the www. version

Production Status is somewhat unusual in that there is no change possible, you can only add a new status.

See Submission Guide: Production Status for details on the choices available.