Step 1: Double-click the Terminal icon located in the Applications > Utilities folder to open a terminal window.

Step 2: Run the following command:
sudo /usr/local/bin/vpn_uninstall
Step 3: Enter your password.
Step 4: You are prompted to remove all profiles and certificates.
- If you answer yes, all binaries, startup scripts, certificates, profiles, and any directories that were created during the installation process are removed.
- If you answer no, all binaries and startup scripts are removed, but certificates, profiles, and the vpnclient.ini file remain.
Example
$ sudo /usr/local/bin/vpn_uninstall
Password:
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Cisco Systems VPN Client Version 4.6 Darwin uninstaller
Copyright (c) 1998-2001 Cisco Systems, Inc. All Rights Reserved.
Please review the license agreement found in license.txt
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Are you certain that you wish to uninstall the Cisco VPN client? [no] yes
Do you wish to remove all existing profiles and certificates? [no] yes
- existing profiles and certificates will be removed.
[ cleaning up installed files and directories... ]
==> removing : /opt/cisco-vpnclient/bin/vpnclient ( VPN dialer )
==> removing: /opt/cisco-vpnclient/bin/ipseclog ( VPN log viewer )
==> removing: /opt/cisco-vpnclient/bin/cvpnd ( VPN daemon )
==> removing: /opt/cisco-vpnclient/bin/cisco_cert_mgr ( VPN certificate manager )
==> unloading NKE: /System/Library/StartupItems/CiscoVPN
Stopping Cisco Systems VPN Driver
kextunload: unload kext /System/Library/Extensions/CiscoVPN.kext succeeded
==> removing: /System/Library/StartupItems/CiscoVPN ( autostart feature )
==> removing: /System/Library/Extensions/CiscoVPN.kext ( IPSec NKE )
==> removing: /etc/opt/cisco-vpnclient ( profiles, certificates, init files )
==> removing: /Library/Frameworks/cisco-vpnclient.framework ( VPNClient API)
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Cisco Systems VPN client uninstall completed successfully.
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$