For easier kills, find the following lines:

AI Damage multiplier - damage AIs take from player
Difficulty_AI_Damage_Easy__d=1.25
Difficulty_AI_Damage_Normal__d=1.0
Difficulty_ AI_Damage_Hard__d=0.75
Difficulty_AI_Damage_Real__d=1.5

...and change the values to:

Difficulty_AI_Damage_Easy__d=4.25
Difficulty_AI_Damage_Normal__d=4.0
Difficulty_AI_D amage_Hard__d=4.75
Difficulty_AI_Damage_Real__d=4.5