Add-AzureRmAccount
Select-AzureRMSubscription -SubscriptionName “mysubscription”
$VirtualMachine = Get-AzureRmVM -ResourceGroupName “ResourceGroupName” -Name “VMName”
Remove-AzureRmVMDataDisk -VM $VirtualMachine -Name “DiskName”
Update-AzureRmVM -ResourceGroupName “ResourceGroupName” -VM $VirtualMachine