I asked some questions about rooting before but I didn't realize it all was supposed to be done on an MT11a with Android 4.0.4. I have 2.3.4, so I just rolled everything back. Where and how can I install this version? I am seeing videos (YouTube, for example) where people have this OS installed in this very same device.
You might want to visit the Update page for Neo V for closer information on how to update. It not only tells you what has changed, but also provides you with the required downloads.
The link is to the UK version. I could not find any link for Argentina, and the Brazil page does not even list the Neo V. So you might want to check around for yourself -- at least that's somewhere to start with.