To activate or deactive a Pro Enhancements subscription find their account in Chargify.

The subscription status is a "Component"

Check the "Current Usage".  To change it, use the settings gear and Toggle On/Off

Whether you're turning Pro Enhancements on or off, make sure the cost does not change when the subscription is updated.  The refund or charge would happen immediately, and most likely you don't want that.

If you need to refund the annual fee after turning the subscription off, look here!