Tour of Duty Achievement in Halo: The Master Chief Collection

The six remastered Halo 2 maps are Bloodline, Stonetown, Zenith, Shrine, Lockdown, and Warlord. In order to knock this achievement out quickly, load up a Custom Game by yourself on each of the new maps. When the match begins, pause the game and select "End Game." This will give you an automatic win, so just repeat this method for the other five maps and the achievement will be yours in no time.