You put the project file and the input csv file in default Visual Web Ripper projects folder, then run this project .
Regarding to change/add csv line:
as you saw, the first section - 2012-04-01-6h means the depart date and time (6h), 2nd section 2012-04-02 is the return date, you can change them by your requirements.
LAX-JFK is the airiine as short name like you saw form fields at first page www.kayak.com
After you ran out the project, you can make a sort by price with all results in VWR output view (Collected data view) , then you will get the lowest cost fights.