To get the Steel Fist one, start at Chapter 4. Then get to the point where you just killed the first three enemies and climbed up the vine. Kill the enemy that's in front of you. Then take cover behind the tall structure on the right side. Then, kill the first two guys, but don't kill the last one. Wait until he's hiding behind cover but a little part of him is sticking out. Then shoot him, and it will hit him in the arm or the leg. Shoot him twice there, then run up to him, and press square. He shuld be down in one punch.