Click Chat with Support and reference this article to arrange for a time to have users disconnected. Please let us know about any integrations your organization has in place, including NXT, and if you have the Queue module set to run during the time.

Note: The process must be completed between Monday - Friday by 5pm ET to ensure there are enough resources in your datacenter to verify that users are able to log in after the process is complete, any web-based applications are restarted, and application integrations are restored without delay.