Here's how to change the chart type in Excel:

1. Select the chart: Click on the chart you want to modify. You'll see the "Chart Tools" contextual tab appear on the ribbon.

2. Access the "Change Chart Type" option: There are two ways to do this:
* From the ribbon: On the "Chart Tools" tab, under the "Design" tab, locate the "Type" group. Click the button labeled "Change Chart Type".
* Right-click menu: Right-click anywhere on the chart itself. A context menu will appear. Select "Change Chart Type" from the menu options.

3. Choose a new chart type: The "Change Chart Type" dialog box will appear. It displays two sections:
* Chart type categories: The left pane lists various chart category groups like Column, Bar, Pie, Line, etc.
* Specific chart types: The right pane shows the specific chart options available within the chosen category from the left pane. Clicking on a category will populate the right pane with its corresponding chart types.

4. Select the desired chart: Browse through the categories and chart options. Click on the specific chart type you want to use for your data.

5. Apply the changes: Click "OK" in the "Change Chart Type" dialog box. Excel will apply the new chart type to your data.

Additional tips:

* You can set a default chart type: If you frequently use a particular chart type, you can set it as the default. After selecting a chart and choosing the desired chart type in the "Change Chart Type" dialog box, look at the top section. You'll see a highlighted chart icon in gray. Right-click this icon and select "Set as Default Chart". Now, whenever you use the keyboard shortcut Alt+F1 to create a chart, it will use your chosen default chart type.
* Changing chart type for a data series: The steps above apply to modifying the entire chart. If you want to change the chart type for a specific data series within a chart (like changing one line in a line chart to a different format), you can click directly on that data series and then follow steps 2-5 to change its chart type.