Updated 06-09-2016 05:44 PM
All the playable characters in the game will have a basic set of skills, Cardio, Wits, Fighting, and shooting. As you play the game you can build up these skills which will eventually unlock a specialization in that basic skill. When a skill specialization becomes available you can hit up on the D Pad to bring up the character page represented by the star icon. Scroll down to the bottom and select one of the skills. Hit X to select the skill you want and then hold X to confirm the skill. Once the specialization skill has been confirmed the achievement will be yours.