In Atlas, go to Communication > Web Input. From the "Page Name" drop down menu, select the page name for the form that you need to update. Next, enter a date range that encompasses the date of the web input record you need to edit. Click "Get Web Input Responses."
In the data grid, highlight the Web Input record that you need to edit. Next, click the "Vertical View" tab. Locate the field that you need to edit. Click on the field, and the field will become editable. Now, make the necessary changes. Once the field has been updated, right click and click "Save Response Changes." The web input record has now been updated.