I have Lufthansa's "Economy Classic" tickets and I can change dates on their website. It's impossible for me to contact their customer service right now.

Does somebody know if I can change the route?

For example, I have round trip NCE-MUC-KBP and I want to change it for NCE-FRA-KRK. I've read the conditions on their website but it's not clear and on the site I've found only how to change the date, not the destination.