Invoke the desktop Report Designer to modify the report definition.
The Report Designer will be started using the ClickOnce deployment technology which is supported out of the box in the Internet Explorer browser. If you are using another browser you can use a browser extension which adds support for the ClickOnce deployment technology. In case ClickOnce is not supported in your browser, clicking the New report button will bring up a notification containing the Report Designer download link. Use the link to download and start the designer manually.