OpenVPN is no longer supported since February 2023.
Once you downloaded Tunnelblick and opened the .dmg file, double click on Tunnelblick icon to install.
Enter your admin password when prompted.
When asked, choose “I have configuration files”.
In the top right corner of your screen you should now see the Tunnelblick icon.
You will see your VPN username and password at the top, followed by the list of config files.
Download the "Eclipse" config files.
Then double-click on the .ovpn files you downloaded to open them. They should open with Tunnelblick.
You may need to enter your admin password...
Select a server and click “Connect”.
Finally, copy your Eclipse username and password from the same page where your downloaded the config files...
... and paste them in.