To edit a comment in Excel, first select the cell that contains the comment. Then, click the Review tab on the ribbon. In the Comments group, click the Edit Comment button. This will open the comment for editing.

You can make changes to the text of the comment, as well as the font and font size. To change the position of the comment, click and drag it to a new location. To resize the comment box, click and drag one of the handles on the sides or corners.

When you are finished making changes, click outside the comment box to save your changes.