Thank you very much for your reply. I've followed the steps in the HOWTO, but I'm confused with this part:
Next, you must set up a route on the server-side LAN gateway to route the VPN client subnet (10.8.0.0/24) to the OpenVPN server (this is only necessary if the OpenVPN server and the LAN gateway are different machines).
Is the LAN gateway my router? In that case, my OpenVPN server (WD Mybooklive running a custom debian jessie) is a different machine. How do I route the VPN client subnet (10.8.0.0/24) to the OpenVPN server on my LAN gateway? Thanks again!