Shared Mailboxes - Office365

Hi all

I'm working on a script that should remove a specific user from all shared mailboxes in Office 365.

So far I have created this:

foreach ($Alias in Get-Mailbox -RecipientTypeDetails SharedMailbox) {

Remove-MailboxPermission -Identity $Alias -User "User@doamin.dk" -AccessRights FullAccess

}

But i'm getting an error.

Cannot process argument transformation on parameter 'Identity'.

Any of you guys that can help me out.

Best Regards

Chris