> I have 70 pieces with ties and slurs here. They are already in Lilypond
> with the correct syntax.
> Now my publisher says he wants that ties look like slurs.
> I couldn't disagree more but I have no choice here.
> Any suggestions how make the ties look like slurs without changing them
> all manually?
It may be possible to write an engraver that would get tie events,
hide ties and create slurs instead. But I see little motivation to do
something that won't improve music typesetting.
You may want to replace ties with macros that can expand to a slur or
to a tie.