To modify the format of a selected cell so it wraps around, you can follow these steps:

1. Select the cell or cells that you want to modify.
2. Right-click on the selected cell(s) and choose "Format Cells" from the context menu.
3. In the "Format Cells" dialog box, click on the "Alignment" tab.
4. Under the "Text control" section, check the box next to "Wrap text".
5. Click "OK" to apply the changes.

Alternatively, you can also use the "Wrap Text" button in the "Home" tab of the ribbon. Simply select the cell(s) you want to modify, click on the "Wrap Text" button, and the text will automatically wrap around within the cell.

That's it! Your selected cell(s) should now have a modified format that wraps around the text. Let me know if you have any other questions or if there's anything else I can help you with.