I have finished it (without mods) by making judicious use of Save/Revert.
In the mission code there is a Mayhem counter (like in Just Cause 2) that increases your 'mayhem' for certain actions. The main things you will want to do are blow up the radio at the little camp in the valley below LZ Connor, blow up the vehicles at the Spartan base, and blow up the trucks at the lighthouse.
Interestingly, BI chose in that mission's code to intentionally set the AI to be almost as dumb as possible. It's basically a gimmick mission.