This is the fifth step in troubleshooting Cisco VPN connection problems on Macintosh. Follow the steps found in the Troubleshooting Guide in order.
Open Terminal.
Type the following at the prompt:
sudo /usr/local/bin/vpn_uninstall
Type Yes when prompted if you are certain that you want to uninstall the VPN Client.
Type Yes when prompted to remove all existing profiles and certificates.
The uninstall process will conclude with a message that the uninstall has completed successfully.