To change your survey, go to Surveys > Manage Surveys, and select 'Edit Survey' from the drop-down menu next to the survey you want to change. Make your changes and click the 'Save Changes' button. Anyone completing the survey after you make your changes will see those changes immediately.
If you have received responses to your survey, we recommend that you only make minor text changes so your survey results remain accurate. Changing the type of question or the intent of a question will not change the responses of people who have already taken the survey. You will receive a warning when you change a survey for which you already have responses.