Originally, I'll fly back from Zurich Airport. Since I will stay in Germany for the last week before I leave Europe, why not try to change the schedule?
Anyways, I successfully made it~!
I called Air France to ask if this change is possible, and to check if they'll charge me any extra money for this change. Guess what? The flight from Frankfurt departs at exactly the same time, and this change won't cost me any!! I've logged in the official website of Air France to check if the change has been truly done by the booking system, and the result satisfied me :) The only thing that needs to be done afterwards is- Go to Frankfurt Airport to check-in for my flight. Then, fly home happily!!
WOW! This change allows me some more time fooling around inside Germany~ What a great news!!!!