To change your Lufthansa flight, you can follow these steps:
Visit the Lufthansa website and navigate to the “Manage Bookings” section.
Enter your booking details, such as your booking code and last name, to access your booking.
Select the flight that you want to change and choose the new flight that you would like to take.
If there is a price difference between your original flight and the new flight, you will need to pay the difference.
Confirm your changes and make any necessary payment.
Alternatively, you can contact Lufthansa’s customer service team by phone or email to request a flight change. Please note that depending on the type of ticket you purchased, there may be fees or restrictions associated with changing your flight.
https://www.airlineticketpolicy.com/change-flights/how-to-change-lufthansa-flight-ticket/