If you no longer need a existing rule, you can delete it. Also, if you need to delete a security group that is used in a rule, you must delete the rule using the security group before the security group can be removed.
From the Dashboard, click the number above UNPROTECTED in the box of the service for which you want to create rules.
The existing rules are displayed.
Click to delete the rule.
The status of the items to which the rule was previously applies is not changed when the rule is deleted.