Weapons Needed:
Torque Bow (12 bows)
Gnasher shotgun (fully loaded)

When the introduction to General RAAM cut-scene has finished, immediately rest up against the cover straight in front of you. Get out your torque bow and fire 1 bow at RAAM. This should send the kryll away. Once the kryll have left RAAM, reload and shoot another bow at RAAM. Do this until you run out of all your 12 bows.
By this time General RAAM should be dangerously close to your cover. This is where the shotgun comes into play. Get out your shotgun and when the time is right and General RAAM sends out his kryll, blind fire RAAM in the hip/chest area. If done correctly this should only take around 10 bullets and the ending cut-scene will begin with RAAM falling to the floor and you have successfully completed the game.
Good Luck!