If still available travelers can purchase Extra excursions at briefing/check-in. Otherwise they can purchase the excursion at info desk daily. All excursion purchases on the resort are cash only.
The deadline to purchase excursions before your trip is 4 week prior to departure. Make sure to log on to your My Profile and save your spot before they sell out! Space is limited, and fill up fast. You are sometimes able to purchase excursions at the resort, however it is cash-only purchases.