You are asking the question 'how to become an expat pilot' (working in a country you don't belong to).
The answer is extremely simple, the same as to become a pilot in your country, because you have first to be an experienced pilot before becoming an expat pilot (with a few exceptions).
That's like asking, I am from London, how to become a rock star in Dublin? Well, first become a rock star which is trickiest part, taking the ferry for Ireland is the simplest.