Stamp notes can be deleted by means of the Comments sidebar. This removes them from the document.
However, you can also proceed as follows:
| 1. | Select the Hand tool  in the Quick access toolbar. |
| 2. | In the document, click on the stamp that you want to delete. |
| 3. | Press the Backspace key or the Del key on your keyboard. |
| Alternatively: Right-click on the stamp, and select Delete in the context menu. |