To reduce the number of licenses in a subscription the recommended options are the following:
Completing an Order Return with Automated Refund
Completing an Order Return without Automated Refund (New Custom UI)
Placing an Order Return without Automated Refund (Legacy)
Placing a Scheduled Order to Reduce the Number of Licenses in a Subscription at Renewal (New Custom UI)
Placing a Scheduled Order to Reduce the Number of Licenses in a Subscription at Renewal (Legacy)