Hi. I have copied this from the Guardian explainer.
"To forcibly remove a dukedom would take an act of parliament, and would represent such a historic move in full view of the public – it has not happened to a senior royal in more than 100 years – that it would most likely cause more reputational damage for the royals.
Andrew is also still a prince. When he was born in 1960, he was automatically such as the son of a monarch. This could only be changed if a letters patent was issued by the king."
Tbh, the more I read, I see the less that has actually been done. He gets to retain the Dukedom and the title Baron Killyleagh. The Duke thing is in abeyance. Which basically means he doesn't use it. I'm not sure that in practice anything has actually happened but he's been told off for making the family look bad and the press have made it into a thing.
I'm not really sure what having a Dukedom means you get, apart from the title HRH. I suspect he'll use that anyway, because it seems that he's meant to be quite petulant about this sort of thing. What's the "promise I won't use my title" worth from chap like him.
Honestly, it seems to me that this family just gets to call each other special names, that presumably mean that you get special family privileges, like the first to serve yourself pudding or something. There must be some financial gain in it somewhere, because Andrew is avaricious but I can't see it. It's probably just his bro saying "you can't open anymore schools because...you know."