To clear a subscriber’s lifetime subscription (which sits underneath any regular subscription they have):
[ ~ ] $ curl -u 2dac9d3d93326f97da4845d407789da232514b48:X -X POST https://spreedly.com/api/v4/meresheep/subscribers/444/clear_lifetime_subscription.xml
A 200 (OK) status code is returned on success. This call will clear the lifetime subscription of the subscriber, which depending on whether they have a non-lifetime subscription active, may or may not make them inactive.