United Airlines flight change at the airport This is another reliable option for changing your United flight. Visit the airport along with your ticket, passport, and other eligible documents. United Airlines flight change via phone call In addition, United Airlines passengers can also seek professional assistance from airline representatives. They will ask you for your account information to carry out the process on your behalf.United Airlines flight change at the airport This is another reliable option for changing your United flight. Visit the airport along with your ticket, passport, and other eligible documents. United Airlines flight change via phone call In addition, United Airlines passengers can also seek professional assistance from airline representatives. They will ask you for your account information to carry out the process on your behalf.