I translated it as "what did you want to have changed", becauase 'ville' also means want in norwegian. Any native speakers know if this translation would be ok?
Yes, that is also a valid translation, but it's not the first interpretation that would've come to mind. If that's what I wanted to say, I think I would prefer saying "Hva var det du ville ha endret"?
So would it accept it if I written "what did you want changed?"