CmdID / PowerShell / Cmdlets / Unregister
Unregister-SmsProxy
From the Windows Server PowerShell reference 6 parameters Its page in the reference
Parameters
-ComputerName, -CN-Credential, -C-Force, -F-OrchestratorComputerName, -OCN-OrchestratorPort, -OP-ProxyCredential, -PCR