For a same-day flight change with Delta Airlines, follow these steps. First, access the official Delta website and log into your account or use your confirmation number. Navigate to the "Change Flight" section and select "Same-Day Change." Ensure eligibility based on your fare type and destination. Review the available flights for the desired change. Pay any relevant fees or fare differences. Confirm the change and check your email for the updated itinerary. Alternatively, revisit the website for verification. If you require assistance, contact Delta's customer service. Remember, eligibility and fees may vary based on fare type and flight availability.