Choose the full itinerary under Manage Booking and confirm the refund amount.
Some fares allow it, but others cancel the full ticket or add fees. Check before confirming.
Skipping your outbound flight without cancelling can cause the airline to cancel your return too.
Keep the confirmation and watch for your refund or credit.
Call +1-800-984-7414 for help, or read this how to cancel a flight booking guide.