HOW TO REMOVE A GUEST FROM ALLOCATION
As mentioned in the tutorials 'How to link a contact to a room via the dashboard' and 'How to link a contact to a room via the booking details' you can link (new) contacts to a room.
If you want to delete a contact you can do this as following:
1/ Go to 'Guests' (in the booking details )
2/ Use the stop sign to delete a contact