Migrate to Office365The migration to Office 365 is a pain. I'm not a fan. I could go on and on but there's almost no point in resisting. I even recommend switching to it to some of my clients.
To start the migration, you need an end-point. That end point needs to have the
WEB SITE NAME: mail.contoso.com
SERVER NAME: contoso-dc (yes, this is the actual computer name).
In the migration, do not setup the users on the new side. The migration will automatically setup the users for you.