This is quite a long process unfortunately. It requires playing through at least 4 seasons. In your second season you will have the opportunity to become a international manager. I suggest picking Spain or Germany. At the end of Your first season you will play a international tournament but it is the euros and for this cheevo you need to win the World Cup which is the 'international cup'. You will get the opportunity to win this at the end of your 4th season. I suggest going for all other cheevos in 'master league' by changing clubs each season while going for this :)