Sites and Active Directory consists of three main components, each of which will need to be removed.
The Connector Service is typically only installed on one or two servers in your network, and is responsible for collecting events from your DCs. You can uninstall this service using Add/Remove Programs from the machine on which it is installed.
Remote Administrator is required for WMI between the Connector and Domain Controllers. This requires a Windows Firewall change. Please make sure that you do not have any other services that require this to open or this will block that communication as well.
To revert these changes on Windows 2003, please run the following
netsh firewall set service type = remoteadmin mode = disable
To revert these changes on Windows 2008 and higher, please run the following
netsh advfirewall firewall set rule group="remote administration" new enable=no
netsh advfirewall set currentprofile settings remotemanagement disable
The OpenDNS_Connector user provides the permissions that the Connector Service requires to read its event logs. These permissions are set by running the Windows Configuration script on your DCs. You can undo the effects of the script by simply deleting this user.
The Virtual Appliances act as DNS forwarders for your network. They are virtual machines that run on either VMWare ESX(i) or Microsoft Hyper-V. They can be removed by simply deleting the virtual machine.
The Umbrella Dashboard contains objects for each of the above components under the "Sites & Active Directory" page. These components should be deleted from the Umbrella Dashboard after taking the above steps.