Get a customer
$customer = Get-PCCustomer -tenantid '<tenant id GUID>'
Get customer user
$user = Get-PCCustomerUser -tenantid $customer.id -userid '<user id>'
Update a customer user
Set-PCCustomerUser -tenantid $customer.id -user $user -userPrincipalName '<new UPN>'
Reset a customer user password
$password = '<password>'
$passwordSecure = $password | ConvertTo-SecureString -AsPlainText -Force
Set-PCCustomerUser -tenantid $customer.id -user $user -password $passwordSecure -forceChangePassword $true/$false