You can delete a trusted certificate from the certificate store when it's no longer used by other policies.
Important
When you remove a certificate from a duplicated policy, it is still used by other policies. To remove it from the certificate store, you must remove it from all policies where it is used.
Task
Select Menu → Policy → Policy Catalog, then select Endpoint Security Firewall from the Products list in the left pane.
From the Category list in the right pane, select Options.
Click the name of an editable policy.
Click Show Advanced.
In the Certificates section, select the certificate you want to remove and click Delete.
Click Save.