Use the certificate method
The Azure module includes cmdlets that help you download and import the certificate.
The Get-AzurePublishSettingsFile cmdlet opens a web page on the Azure Management Portal, from which you can download the subscription information. The information is contained in a .publishsettings file.
The Import-AzurePublishSettingsFile imports the .publishsettings file for use by the module. This file includes a management certificate that has security credentials.
Stop-AzureVM -ServiceName “myServiceName” -Name “myName” -StayProvisioned