I am booked on Lufthansa through Expedia. Flying USA to Germany, round trip, economy plus (Booking class: Economy / Coach W). There are three people on my booking. Only one of us needs to change our return flight to an earlier travel date. Do I just book a new, single, one-way return ticket and no-show on the original return ticket? Expedia is saying I may get blacklisted if I don't let them know ahead of time my intention to not fly back on the original return ticket. Please, what is the best, most cost-effective way for me to make this change to one of our tickets?