During installation, you will be asked for your mac admin password. You will also be asked if you would like to launch, select launch:
You will then be asked if you have a configuration file, select 'I Have configuration File':
If successful, you will see the tunnleblick icon on the menu bar:
Double click on the configuration file you just downloaded to install it. When asked, select install 'only me' or select 'All user' if you want other users on your mac to use VPNod
You will then be asked to input your mac admin password to complete installation.
If successful, you will see the new connection available, click on it to connect:
Now just enter your vpnod.com username and password.
If connected, you can use the tunnleblick menu to disconnect: