Unless you are a citizen of Argentina or Chile, you are gonna need a visa.
You wont get one just by applying, you will need to some kind of hookup to facilitate the process.
So, you need to be a certified instructor here who happens to know someone whos in charge of a ski school down there. If you pull that off you will get a free pass and you wont make shit for money.
Alternativey, you can try to get a job guiding for an american company, in which case youll get decent pay but no free pass. In order to get a job you will need guiding certifications, atleast passable spanish, and you will need to have spent a few summers down there already.