Open the downloaded disk image file (which mounts the disk image).
Drag the Tunnelblick icon (may be labeled “Tunnelblick.app”) to your Applications folder.
After logging in to the Access Server’s Client Web Server, download the client.ovpn file and place it in the ~/Library/Application Support/Tunnelblick/Configurations folder on the Mac.
In new systems if you can’t find the folder just double click on client.ovpn.
Run Tunnelblick by double-clicking its icon in the Applications folder.
The first time Tunnelblick is run on a given Mac, it will ask the user for the user’s password (on the Mac system). This is because Tunnelblick must have root privileges to run, as it modifies network settings as part of connecting to the VPN.