Login to your DD-WRT control panel through the web browser, for example https://192.168.1.1
Click on Setup and then on Basic Setup.
Under the Network Address Server Settings (DHCP), Change Static DNS 1 and 2 to 220.127.116.11 and 18.104.22.168
Then click Save and Apply Settings.
Click on Administration and then Commands.
Download PrivateVPN DD-WRT OpenVPN script paste all text into the Command shell field and edit following lines: USERNAME="Enter your user name for PrivateVPN" PASSWORD="Enter your password for PrivateVPN" remote Change only the server address and not the port number. For example: us-nyc.privatevpn.com, which will be: remote us-nyc.privatevpn.com 1194
You'll find the server list here: Server list
When you've edited USERNAME, PASSWORD and server, click on Save Startup.
Click on Management and scroll to the bottom of the page and click Reboot Router.
Wait some minutes for the router to reboot and the VPN connection to establish.