Deleting Data with an Expired Retention Period 
As a system administrator, you can trigger the deletion of the archived KMC data whose retention period has expired. To do so, use the Retention Management report. You can either trigger the deletion of KMC archiving objects with an expired retention period immediately, or define a schedule for the execution of the report.
Prerequisites
You have the System Admin portal role assigned to your user.
Procedure
In the portal, navigate to
System Administration 
System Configuration Knowledge Management Content Management 
.In the navigation panel, choose
Related Links Archiving Tools Trigger Archiving Retention Management .Choose Start and specify a name for the report.
On the Commands tab page, choose Delete Expired.
Choose Start.
Result
The report deletes all archived KMC archiving objects whose retention period has expired.