For this, you will first need a scout. Go to Youth Academy and then to Scout Network. Here you can hire up to three scouts. Hire one, go back and Continue. The next day you'll receive an e-mail the scout has arrived. Then you can send him anywhere you want in the world. Choose a country and how long he has to scout.
When he's scouting, it'll take about a month before you receive the first report. Offer ANY player in the report to join your youth squad. A day later, you'll receive e-mail about their acceptance and the achievement unlocks.
If the player refuses, it's like buying players from other clubs; you simply didn't offer them enough cash.