Open the pause menu, then hold the left shoulder button and enter:
B, X, A, Y, Left Thumbstick, Y, A, X, B, Right Thumbstick - Big Heads
Left Thumbstick, Left Thumbstick, A, Right Thumbstick, Right Thumbstick, B, Left Thumbstick, Left Thumbstick, X, Right Thumbstick, Right Thumbstick, Y - Change Tracer Color
Left Thumbstick, Right Thumbstick, Left Thumbstick, Right Thumbstick, A, B, Left Thumbstick, Right Thumbstick, Left Thumbstick, Right Thumbstick, X, Y - One Shot Kills
A, A, B, B, X, X, Y, Y, A, B, X, Y - Increase Ragdoll Strength
X, B, X, B, Left Thumbstick, Left Thumbstick, Y, A, Y, A, Right Thumbstick, Right Thumbstick - Third-person View
Calypso Casino Rooftop Glitch
This trick requires you and a friend/squad member on the Calypso Casino multiplayer map. Make your way up the stairs towards the helipad where you must bring the Intel on an attack and defend mission. Once you reach the top of the stairs there should be two boxes overlooking the top floor where you can take cover behind. Go to the very first box closest to the stairs. Press Cover about two or three times at the right corner of the box then hold Cover. You should now be floating in the air. Do not move until your friend runs up behind you and runs into your back. When your teammate is running into you, begin pressing Forward and he will "push" you on top of the box. Once you are on top of the boxes, there should be a railing next to you. Walk onto the railing then run towards the stairs and the railing should lead you around a previously fenced off area where you can drop down into and cover all three entrances to the helipad if your team is defending the Intel on the helipad. To continue, keep running on the railing past the fenced off area. You should be running towards the roof that connects with the elevator building. Run to the very end of the railing then run onto the roof. You now have complete coverage of the entire roof area of the map. It is recommended that you either watch the repels or elevator door if you have an SMG/rifle, or watch the far repel if you have a sniper rifle. If you only have a shotgun do not bother going up there.