Remote SIP Phones / VPN

SkykingOH - I am finally getting around to this, Any idea if a good doc was ever created? I have yealink phones,and I built a separate openvpn server and attached to the freepbx network. I can vpn into that network via putty. I can try the trial and error method, but was hoping for a doc, or some good verbiage about what I need to do now to get the remote phones working. Thanks.