1. In the main menu, hit Game Modes, then Contracts. Create a contract. I chose ICA facility and just marked one of the mechanics to kill. Kill them and finish it to publish the contract.
2. Play it sloppily. Best way is to kill your target and then an extra target not apart of the contract. This will give you a low score.
3. Play it again. This time only shooting your target and then immediately escaping. This will automatically give you a higher score than before because you didn't kill anyone extra.
4. Achievement unlocked.