Maybe a better way would be to bring the system into an Apple Store when you arrive here in the states to let them fix it (don't forget to pack it in your stowed luggage, not carry on). I would line up an appointment before you leave Brazil at the closest Apple Store where you will be staying.
What I fear here is you get all of this stuff only to find out it was still something else! While it might be more expensive than doing it your self I think you'll be happier in the end.