I am assuming you are referring to the Tour 1 flight plan download package from the Misty's Flying Club web page. When you open the zip file, there will be several folders inside. One folder contains the flight plans. Place that folder into your sim's flightplans folder. ("Prepar3D v4 Files" folder, etc.)
You must choose your flight plans the same way as a normal flight. Depending on your sim version, load your selected flight plan into the sim's Flight Planner. Open your sim's flight planner. When the "Load Flight Plan" page comes up, click on the Browse... button. Browse to the folder (usually called "FP") containing the collection of flight plans for that tour, and select your flight plans from there. Browse to, and select that folder within the flight planner.
Alternately, place the tour flight plans in the main folder with your other flight plan. Then they will be on the list that is presented by default.