This is not a VMWare question but a Windows one and your question is quite poorly put together, please put in a little more effort in future.
No you don't need to do anything before starting up the machines (in fact it's not possible to change the domain without doing so) and you do everything as normal. Start up the machine, change the domain, restart the machine.
All the users on the VM will be gone; they aren't "on the machine" but instead are on the domain controller. Any users you want to be able to logon to the machine after it is in the new domain need to exist on the new domain controller.