To reset a local admin password, you need first to define the virtual machine that you need to work with. To do this, you can use the Get-AzureRmVm command, coupled with Set-AzureRmVMAccessExtension. Run the following four commands to set up the variables needed to reset the admin password on myVM1:

$resourceGroupName = "VMLab"

$vmName = "myVM1"

$name = "ResetPassword"

$location = "EastUS"

Once you've set up the variables using the preceding commands, update the local admin credentials for the virtual machine by running the following command:

$creds = Get-Credential

When prompted for credentials, supply the existing local admin username but give it a new password.

After supplying the new local admin credentials, run the Set-AzureRmVMAccessExtension command to actually set the new credentials on the virtual machine:

Set-AzureRmVMAccessExtension `
 -ResourceGroupName $resourceGroupName `
 -VMName $vmName `
 -Name $name `
 -Location $location `
 -Credential $creds `
 -TypeHandlerVersion "2.0"

Once this is complete, the username will have a new password! This technique is useful if you're able to authenticate to your Azure subscription but have forgotten the local password on a virtual machine.