You will now see a list of names for that particular event you just chose.
Look at the peoples names. They are in a column called names. There is a checkbox next to the names column at the top. Check this box. This will automatically check EVERYONES name in that list.
It will ask you for a filename. Type in the FULL file name with extention. For example, you would type in retreat.csv or supper.csv and NOT just retreat or supper.
Click the save button in the popup box and save the file to your computer.