Explanation/Reference:
Explanation:
See step 2) and step 5) below.
To convert an existing domain to a single sign-on domain, follow these steps.
Open the Microsoft Azure Active Directory Module.

Run $cred=Get-Credential. When the cmdlet prompts you for credentials, type your cloud service

administrator account credentials.
Run Connect-MsolService -Credential $cred. This cmdlet connects you to Azure AD. Creating a

context that connects you to Azure AD is required before running any of the additional cmdlets installed by the tool.
Run Set-MsolAdfscontext -Computer <AD FS primary server>, where <AD FS primary server> is the

internal FQDN name of the primary AD FS server. This cmdlet creates a context that connects you to AD FS.
Run Convert-MsolDomainToFederated -DomainName<domain>, where <domain> is the domain to be

converted. This cmdlet changes the domain from standard authentication to single sign-on.
References: https://msdn.microsoft.com/en-us/library/azure/jj205461.aspx