Thank you for the reply. As per the link, "Fee for making a change to or canceling international tickets that do not originate in the U.S. 30 or fewer days before departure" is $125.
So, if I make a change before 31 days or more, it should be free correct?
Also, it should not matter that flight is from Lufthansa as far as I book through United, correct?
hanks again for your time and patience.