I was just about to start a similar thread using the name I've heard it called on the BBC: "Megxit"

Comes now this royal kerfuffle about the young prince and his young bride and their baby. Sounds like they want to make a living on their own, although I dont think I'll see Harry belcoming a Walmart greeter or pump jockey. The subtext I'm getting from reading between the lines is they expect to make a comfortable living suing tabloids. There are worse ways to make a Pound or a Dollar. Maybe they've been transfering their savings to Euros and they expect the European currency to rise.
I read this great little book some time ago about a Frenchman who exchanged his title for a regular name and became American.

Ted Morgan, the former Sanche de Gramont On Becoming American

also at Goodreads:
On Becoming American