How to change a nested property in an object?

Say I have an object like the following:

myObject{
   name: '...',
   label: '...',
   menuSettings: {
      rightAlignment: true,
      colours: [...],
   },
}

I would like to change the rightAlignment value to be false. I’m having quite a bit of trouble trying to access and modify just this value, without having to rewrite the rest of the object. I tried myObject.find(…) which didn’t quite suit, and now was trying

Object.assign(this.myObject, {menuSettings: {rightAlignment: false}});

Which wasn’t working because I’m guessing I didn’t access the property correctly. Is there any way to cleanly do this?