moving single workstation to other location without domain

Hi,

I have one user who is a member of a windows server 2008 domain, which pc is
moved to his house.
What is the way that this user still can logon to the domain in a secure
way, without placing a dc on that site?
What is the advised method for this?
Is there an easy way this user can connect over the internet by vpn
Is this easy to install on the dc (though maybe not preferred on the dc, but
I have nothing else at this moment) ?

regards,
Marcel