I had to cancel just the return leg of my Delta trip last month, and honestly, the website wasn’t very clear. After fumbling around online, I finally just called 877-297-0699. A rep picked up quickly, confirmed my booking, and walked me through canceling only the segment I didn’t need. It took less than 10 minutes, and they even helped me double-check the fare rules so I didn’t lose out on credits. If you’re stuck or worried about messing it up online, that number is hands-down the fastest way to change or cancel a single leg without stress.