You must go to the West Point Visitor Center (2107 New South Post Road) with a real ID to get a pass. Please do not wait until right before the ceremony to get your pass. For more information, visit https://home.army.mil/westpoint/about/visitor-information
If you are not staying overnight at the Bear Mountain Inn, parking passes are required until 5pm. To get a pass you must visit the toll booth at the main lodge, and if you are a guest you will receive your pass upon checking in. If you park there after 5pm (cocktail hour starts at 5:30pm) you won't need a pass!