Just in case I can help someone else to have these documents legalised there are 3 steps involved;
1. To sign in presence of a notar, there are many on Lavelle 1300 block of the street approx 100 pesos per page
2. Then have the notar certified by the school of notars (Colegio publico de escrisavos) 1833 Ave Las Heras y Callao approx 70 pesos per page. Hours 9.30am-3pm
3. Take it to the Ministerio de relaciones exteriores, 819 Avenales. Hours 8.30am-1.30pm
Cheers hope to help someone!