If you want to delete (withdraw) an approved leave request, find it in the list on the Dashboard under the MY DOCUMENTS component – ABSENCES section, and open it (approved requests are marked with a checkmark symbol). In the open document, click MODIFY REQUEST in the top left panel and then click the DELETE button in the REQUEST DETAILS section. Confirm the change by clicking SEND FOR APPROVAL.

You can find more information on this topic in the article: Modifying or withdrawing a leave request.