Honestly, I think the only way they can ever change the narrative around them is to just shut up. Stop complaining incessantly about every little thing (sometimes the press will embellish/lie - they don't need to respond to every single falsehood); don't make drama out of nothing (the "high-speed" car chase in Manhattan) and just live quiet, happy lives.
I genuinely believe that Meghan was treated badly when she came - but I also think that was more social media than the actual press, and definitely the public, who cheered loudly for her. I think if they just turned their phones off and stopped monitoring everything, they would be much happier - Harry's own book pretty much confirmed every negative story about them was true.
I can understand why they are returning. I suspect America is not a great place to live at the moment, and they are both significant targets, which is why I've never understood the narrative they were safer living there and safer visiting Columbia and Ukraine than visiting the UK.
But I also think theres significant truth in needing to make amends now, before Wiliam becomes King, because you know damn well he won't have anything to do with them. When the queen was alive and with the power, everything was Charles' fault. As soon as he took the throne, that all shifted to William.
Where I think their behaviour was despicable was doing the Oprah interview, publicly claiming that they were racist for not giving the kids titles, despite KNOWING the letters patent would be relevant, and then Harry claiming he never said that in the interview with ITV years later. I think the way they treated Charles with the plane incident when the Queen was literally dying is something that can't be forgiven, let alone the accidental 'leaking' of C&C names to Omid Scobie with the book....