To delete a survey quota, follow these steps:
Click on the "Surveys" tab located at the top of the administrative user interface.
Select the Survey you want to edit in the list of Surveys below the "Surveys" small tab located on the left hand side of the administrative user interface.
Click on the "Edit" button.
In the Survey window, click on the "Advanced Settings" tab then click on the "Quotas" tab.
In the grid of survey quotas, click on the survey quota you want to delete.
Click on the "Delete" button.