Near the beginning of the game, after making it to the Zephyr Transit safe house you'll be given a mission to go see Birdman. On your way to him you'll get a call from your friend Nomad, asking you to see him. Meeting up with Nomad will start the mission Old Friends. This mission will introduce you to the Conglomerate terminals that are scattered around the city and will allow you to start stealing their parts from then on.
There are different types of terminals but all their parts count towards this achievement. There are more than enough terminals in each city zone and you'll find plenty of them during normal play. As soon as you collect any 10 parts from across the city the achievement will pop.