Change primary SMTP address using powershell for AD NOT Exchange

I am in a Office 365 Hybrid mode, this question has been asked on the Office 365 forums and I was directed here.

Using PowerShell for Exchange 2007+ its a fairly simple process to change the primary SMTP.

Using a PowerShell script with a couple simple variables this is what I would use for Exchange:

Set-MailBox "$getUsername" -EmailAddressPolicyEnabled $false -PrimarySmtpAddress $getSMTP

Is there any equivalent or something similar to this for AD PowerShell?