You can delete a specified report element.
DELETE <webiURL>/documents/{documentId}/reports/{reportId}/elements/{elementId}
Response type: application/xml or application/json
The response is a message stating the success or failure of the request.
DELETE <webiURL>/documents/5022/reports/3/elements/22
<success> <message>The resource of type 'Report element' with identifier '22' has been successfully deleted.</message> <id>22</id> </success>