You can manage a guest's byts within the "Byts" tab of a Guest Profile. 

To remove a byt, uncheck the byt using the checkbox to the left of the byt name. This will remove the byt from the Guest Profile and the byt will not be visible on the Guest Itinerary. 

To change the quantity of a byt, use up or down arrows or manually enter the quantity of the byt in the "Byt Quantity" field. Please note, the quantities that are displayed are defaulted from the "Create New Group" page. Click the green check button to save changes to the byt quantities.