There are two ways for editing diagram data of a chart linked with an Excel® file:
Editing diagram data directly in PowerPoint®:
First, open the PowerPoint® presentation including the diagram which you wish to edit. Click on the diagram, and an action bar will automatically appear above the selected chart. Now choose the action point „Data“. The embedded Excel® table will open and you can make your desired changes directly.
Please note that this table ist not the Excel® file that is linked to the chart. Any changes made here have no effect to the original linked Excel® table. If the chart is updated from the actual linked file, manual changes will be discarded.
Editing Excel® table in the linked file:
Open the Excel® file that is linked to the chart you wish to edit. Make the desired changes within the Excel® table and click on „Save“. Now open the presentation that includes the linked chart.
If the option „Refresh data on open“ is activated, the chart is updated automatically once the presentation is opened. If this option is deactivated, a manual update is possible by clicking on the action point „Refresh“ in the action bar above the selected chart.