Originally Posted by flysurfer
I...LAX-xJFK(SQ)-xFRA-MUC could not only be changed to LAX-xJFK(LH)-xFRA-MUC, but also to something like LAX-xZRH-MUC or LAX-MUC without charge. True?
Not true.
Changing the city pairs in any segment is a rerouting that requires a ticket re-issue. Unless the re-routing is involuntary, you pay the re-issue fee.