How to get 8.1 on my Samsung Ativ S ?

[GrandGerminator]

HellO.
I know that the 8.1 update (from 8.0) is available for the Samsung Ativ S in Italia and Germany... But I'm still waiting it in France.
I'm looking for a way to get the update without getting the phone unusable.
There is two things I'm thinking about :

1 - Could it work with the developer preview ?
2 - If I follow the currents steps to get 8.1 update 2 thanks to the Insider app (http://wmpoweruser.com/windows-insider-app-delivers-windows-phone-8-1-update-2-to-any-handset-which-does-not-support-w10m-tp/) ?

Do you have an advice ?

Thanks