Argus Mercenary costume - In Machi Akko, go to the bar and use the microphone. Look behind you for a keycard. Go back to the hallway with three doors, and use it on the closet.
Camouflage Sam costume - In the Lighthouse level, snipe the man on the roof, but don't rappel down. On the high right corner is the costume.
Displace Mercenary costume - in Display level Go to floor three. Use the optic cable to see which room has the green package. Enter the room, and use keypad code 5800
Displace suit - Room next to the room where you have a last chance to save, code is 5800
Masked Sam costume - In the Penthouse level, go to Zherkezhi's apartment, and go to the first room on the top floor. Go down the long, dark hall and type 5698 in the pad.
National Guard costume - In the Manhattan Streets level, go to the open area before the penthouse. Climb the pipe, jump left, and go down to the next platform, in the corner.
Shadownet Agent costume - In Kokubo Sosho, go down the elevator, where lasers are at teh bottom. Find a ladder to climb back up. The room will have lasers and the costume.
Short sleeved Sam costume - in Bank level Go to the small vault left of the computer and use the lockpick
Snow Guard costume - in Battery level Get the wrench, and go to the U shaped room. Enter the keycard room, take out the guard, climb on the crate, and bash next crate
Thermal Suit costume - in Hokkaido level Find the wrench, and find the man who is shooting on the roof, get to him and fall through the vent, exiting the room, and bash the door.