Migrate language(Internationalization change) en > en-us

Tried to find an answer to this but couldn’t find much.

Working with latest strapi, I have stumbled upon a little issue.

Strapi was initially set with language ‘en’ however business that I am working with would love to switch to ‘en-us’. While I know I can create content in multiple languages and am well aware how that works. I don’t want my clients having to re-do every single piece of content they have just to change from en to en-us.

So with that in mind, how does one migrate all of the content to a different locale and making that a default locale? But hopefully without having to create all new uids etc.
Is there even a way to do that?