Wwo players are required for this trick. Go to the building with the MG 42 (the building that is not destroyed) and have one player jump on top of the MG 42. Have the other player start jumping behind him while the player on the MG 42 faces out the window. When the jumping player is in mid-air, have the other player get on the MG 42. He should become invisible but still able to shoot the turret. He will be almost invincible, requiring two or three grenades directly on him to kill him. Note: This only works if the player is directly on top of the MG 42.