How do i connect my time attendance device to VPN

We have 15 time attendance device at different locations for staff attendance.We have to connect all these attendance device in one server so that we can download the attendance log. We have windows server 2008 at our headoffice and the attendance software is installed in this server. Can you please advice me how do i configure VPN server in windows server 2008 and how do i connect all these device through VPN.