Welcome,
I apologize as the concept of "easy" varies from person to person. Everyone has different preferences regarding what they consider fun, efficient, or convenient.
In my travel experiences, including visits to Argentina and Brazil, I've generally been able to withdraw cash from local ATMs. The key factors are whether the first attempt is successful and the associated fees. My banks don't reimburse fees, and one adds its own. I've encountered ATMs dispensing multiple currencies mainly in Europe.
I can also purchase foreign currency through one of my banks. Additionally, I've used Western Union during my travels, as well as my credit card for cash advances from ATMs. However, cash advances accrue interest from day one, so caution is advised.
I experiment with various methods to understand the processes and associated charges. During my travels, I've used foreign currency exchanges at airports, including IGU, to obtain Brazilian Real and convert excess foreign currency. ATMs are available both at the park and in town, though their functionality and availability can vary.
Regarding Ezeiza International Airport (EZE) or Jorge Newbery Airfield (AEP) in Buenos Aires, I don't recall seeing universal ATMs. While foreign currency exchange offices are present, it's worth noting that prices at airports can be higher. There are also street vendors known as "Gambios" in Buenos Aires, offering cash exchange, but I haven't utilized them for Argentine Pesos or any other currency.
If you plan to stay overnight on the Brazilian side, consider inquiring about the closest ATMs for your convenience.
Best of luck with your travels.
