Step 1. In the dashboard click 'LISTS' and choose the list you want to open. Click 'view' to open the list. 

Step 2. In the list settings area click 'FILTER' and select 'OPENDED' in the dropdown selection and click 'APPLY FILTER' then click 'EXPORT' to continue.

 
Step 3. Carefully choose the fields to export by checking off the boxes and select the appropriate delimiter between fields and click  'EXPORT'.