As of my last knowledge update in September 2021, I can provide you with general information about Southwest Airlines' policies regarding managing bookings, cancellations, and flight changes. However, please note that airline policies can change over time, so it's recommended to visit the official Southwest Airlines website or contact their customer service for the most up-to-date information.

1. Managing Bookings: Southwest Airlines typically allows passengers to manage their bookings online through their website or mobile app. You can log in to your account and access your reservation to make changes to your flight, such as updating passenger information, contact details, or adding EarlyBird Check-In. This is usually done under the "Manage Reservations" or similar section on their website.

2. Cancellation Policy: Southwest Airlines is known for its flexible cancellation policy. As of my last update, they offered a unique policy that allows passengers to cancel their flights without a cancellation fee. Instead of charging a fee, the value of the canceled flight is usually held as a "credit" for future use. This credit can be applied to a new booking within a specific timeframe (often up to a year from the original booking date) and can be used for the same passenger or another person. Keep in mind that fare differences may apply when rebooking.

3. Flight Change Policy: Southwest Airlines also has a customer-friendly flight change policy. Passengers can change their flights without paying a change fee, but they will be responsible for any difference in fare if the new flight is more expensive. Any remaining balance after the fare difference is applied will be held as a credit for future use.

It's important to note that the policies can vary based on factors such as the type of fare purchased and the time of booking. Also, while Southwest's policies are generally quite lenient, it's advisable to review the specific terms and conditions associated with your booking, as well as to check for any updates on their official website.

For the most accurate and current information, please visit the official Southwest Airlines website or contact their customer service directly. Keep in mind that my information might be outdated, as my last update was in September 2021.