sudo apt-get install openvpn
sudo cp /path/to/openvpn/config/file /etc/openvpn/
sudo openvpn --config /etc/openvpn/config_file.ovpn
sudo openvpn --config /etc/openvpn/server1/<config_file>.ovpn --route-up '/sbin/ip route add <server2_ip> via <server1_ip>'
sudo openvpn --config /etc/openvpn/server2/<config_file>.ovpn