When a customer makes a bundle booking or any other class booking, they receive a confirmation email. They can simply go to the booking confirmation email and select 'Manage Booking.' from there they can manage their booking, select additional dates for the bundle, or unselect the chosen ones.
Alternatively, if you allow them to create a profile, they can click on 'Profile' to sign up for a new account or log in. The bookings will appear on the account with the same email used for the booking. Click on 'Purchases', select 'More Info', and they can manage their booking from there.
Here is a video guide showing how customers can manage their bundles or any other bookings with Baluu: