This is accumulates over all of your wrecking crew games. You can check your progress in the Statistics menu, hit to take you to the achievement progress. Just inflict as much damage as possible in each match. Turn barrels 'ON' & Building Collapse to 'High'. These will both help you take down buildings faster.
Try these setting:
Mode: Total Chaos
Weapon: Thermobaric Rocket
Building Collapse: High
Players, Backpack, and Rounds to Win can be set to whatever helps.
Right when the game starts, immediately begin shooting rockets at the nearest building, aim at the lowest level to get the most points. You can easily rack up to 100,000 to 150,000 every round.