How do I Alter/Modify a Reservation Within the Acceptable Cancelation Window? You can modify your Tee Time if it is within the acceptable cancelation window. To read more about the specifics of the Tee Time cancellation policy, click here. Open the app and tap Me. Tap the three dots in the top right corner. Tap Transaction History. Find the Tee Time Reservation you wish to cancel and tap to open the Tee Time Reservation screen. At the bottom of the screen, tap Cancel Order.