Managing the UCD 
The administration of the UCD is performed using the UCD Cleanup Tool. This tool provides the ability to delete items from the UCD.
To delete items from the UCD:
Access the UCD Cleanup Tool using the following URL: http://<server>:<port>/irj/servlet/prt/portal/prtroot/com.sap.portal.pcd.admintools.ucdadmin.default.
Enter a principal name and choose Show.
A table of UCD users is displayed.
Select one or more users to remove, and choose Remove.
When you are done, choose Close.
Note
Deletion of a portal user deletes that user’s context in the UCD as well.