You can find all your survey responses on:
This can be accessed by clicking the Responses tab on the top menu:
On the Responses tab, simply select the survey name and adjust your filters, including the time period, to show the responses that match your criteria. Once you have adjusted the filters, click on the 'Apply" button to run the query. Your responses will be displayed in the column on the right.
If you have the necessary privileges, you will be able to delete an individual response.
To delete an individual response, click on the Delete icon for that response. You will be asked to confirm your action. Click on the Yes button in the alert that opens up. The response will now be deleted and will no longer influence your metric scores or count towards any statistics.