Passengers need to pay difference fares between two flights if the new flight fare is high as compared to the current flight fare. If the new flight ticket fare is less than the current flight fare then, the rest of the amount will automatically convert into the travel points which will use for the next flight ticket booking. Contact Aeromexico Customer Service to get more details on Aeromexico Flight Change Policy & Aeromexico live person are there to help you 24*7.