You can cancel a customer's booking from the session Attendees screen. This is found at Schedule>click on session's Details button>click on Attendees tab.
Click on the customer's name in the Attending list
Click on Cancel booking
To swap a customer's booking you cancel it and then add them to a different session. A demo video of how to do this is below.
You may also be interested in our Auto-refund product which enables you to auto-gift a credit when someone cancels in line with your cancellation policy, saving you the hassle of having to action the swap.
Cancel and swapping bookings
You may also be interested in:
Auto-refund