Currently, an existing report in the Report Library cannot be directly altered in any form by an admin; however, anyone can make a copy of a report by copying it to My Reports and altering it there.
How a report can be altered in My Reports depends on the original structure of the report.
1. If the original report was created using a custom query, then the information in the Query Tab of the copy in My Reports can be altered by typing changes directly in the Query Tab.
2. If the original report was not created using a custom query, then the information in the Query Tab of the copy in My Reports can only be altered by changing the fields and parameters of the report.
For more information about custom reports and customer queries see page 67 of the Report Manager User Guide available online at https://support.quest.com/enterprise-reporter/2.5.1/technical-documents