first find the passport/DNI office in your town. go there and get a number, wait, when your number is called go up to the counter and register to change your address, get a piece of paper, carry the piece of paper 6 city blocks to the other municipal building where you wait in line and pay a 300ARS fee.walk back 6 blocks to the original building and take a number, wait, get called and hand over the paper showing you paid, go sit at the desk where the lady asks you your new address, retakes your picture and gets your finger prints again. the lady will give you another sheet of paper that YOU HAVE TO HAVE when the delivery guy comes to deliver your new DNI. The delivery service will not release your DNI to you without this paper even if you have your passport or god himself vouching for you.
Altogether that process takes about 1.5-2 hours.
It has been 3 weeks now and I still don't have my new address DNI. In a month I will travel to BA to do my work visa paperwork over again and get a new DNI.
I did manage to get a driver's license from start to finish with the license in hand in the span of 2 hours. They misspelled my name the first time (of course) and cut a new license in 10 minutes.I got a 96% of a multiple choice castellano test and I don't really even speak spanish.