Foreigners Studying at UBA

I'm having extraordinary difficulty trying to figure out how/where/when a foreigner signs up for classes (or even applies) at UBA. Dates of inscription dictated by the first letter of my last name, standardized tests I've never taken, and a bizarre lack of information on the website have me very confused. Of course, it seems that if I pay a US-based program, I don't even have to apply directly. If anyone has gone through the process of arriving to BA and registering for classes, please help me out. I'm just looking for a quick step-by-step. Many thanks.
UBA is completely chaotic. Argentines have told me how very difficult it is to get through the system. I have no idea what you want to study however I can only say that to do so you will have to be extremely persistent and patient. Why not look into one of the better private universities such as UCA. You will find everything better organized and professors will even show up for class!