Actually you are renewing your visa, not your DNI and it must be done at migraciones. You need to demonstrate that you still qualify for temporary residency just as you did when your visa was first granted. You won't need a new criminal report from your home country, but you will need to show proof of income for the visa pensionado or financero, enrollment in a recognized university for a student visa, or proof of continuing employment for a work visa, etc. You will also need a new penales antecedents in Argentina. And take copies of every page of your passport as well as your DNI. You can renew up to sixty days in advance. There is a 30 grace period if you renew after the expiration date but the fee will than be $900 pesos instead of $600. Be sure that any new documents you submit are less than 60 days old.