You can clear all the policies from your proxy from the Command Line Interface (CLI). To do this you will need to have a serial cable or SSH connection to the proxy and issue the following commands:
login as: admin
Enter configuration commands, one per line. End with CTRL-Z.
WARNING: This will clear local, central, forward and VPM policy. Are you sure you want to reset ALL policy files? (y or n)
NOTE: This will clear all policy in the proxy. Use caution when using this command.