To edit a report in the browser Advanced Report Designer, edit the report and click the Edit Advanced Layout button in step 5 of the report wizard.

This button is not available for cross-tab or chart reports or if you are not using a Report Designer license.

The Advanced Report Designer retrieves the data for the report so it can size fields as necessary and allow you to preview the report in the Report Layout Designer, so you may be asked to specify values for any ask-at-runtime filter conditions.

A report's advanced layout is edited in the Report Designer window.