This will help you configure OpenVPN on any Asus router running ASUSWRT, including
- RT-N66U
- RT-AC56U
- RT-AC66U
- RT-AC68U
- RT-AC68P
- RT-AC87U
- RT-AC3200
- RT-AC88U
- RT-AC3100
- RT-AC5300
1) Download one or more of the VanishedVPN OpenVPN config files from here, depending on which VPN(s) you intend to setup. For example, if you're intending to unblock US Netflix, download the USA config file.
2) Follow the informative guide at VPNUniversity.com