Removing a Seat License
You will need to adjust the number of seat licenses in Payment & Billing if you're downgrading the number of active users. Unused user seat licenses will continue to be charged unless action by the admin is taken and all changes must be made prior to the renewal date in order to be reflected on the renewal payment. This multi-step process mitigates any billing charges since most accounts replace a user immediately rather than later down the road.
Adjust the number of licenses by navigating to Payment & Billing. Select Update Subscription > Change (license count) > Review and Finish > Downgrade.