To customize the Quick Access Toolbar in Excel and include the Redo button, follow these steps: 1. Click on the drop-down arrow next to the Quick Access Toolbar. 2. Select More Commands. 3. From the drop-down list, select All Commands. 4. Scroll down until you find the Redo command, select it and click the Add button to add it to the Quick Access Toolbar. 5. Click OK to save the changes.