edit columns in google spreadsheet

Inside of this guide you can find how to integrate your form with Google Spreadsheet: 

http://www.jotform.com/help/228-How-to-Integrate-Form-with-Google-Spreadsheet 

You can make changes on your Google Spreadsheet. However if you change title of column that will break integration for that field and data will no longer be passed to that field. 

Hope this will help. let us know if you need further assistance.