It is easy to remove a survey and all its responses from your library.
Delete a survey
To delete a survey, click on the three-dot icon on the right corner of your survey, and select Delete.
Delete multiple surveys
You can also delete surveys in bulk. To do that, select the surveys by clicking the checkbox in the top-right corner and click Delete button at the top.
Accept the warning message points:
Take a look here for a video instruction: