Bros At the Close Achievement

This was for me the hardest one after the "No One Left Behind" in Spartan Ops.... As soon as the level starts. RUN! lol, You got to get ahead of everyone and kill the enemies the fastest way possible. Make them shoot you. After you finish the first round of enemies, change all of your marines weapons for forerunner ones. I don't know why, but doesn't matter which weapon they are, as long as they are forerunner, they will serve better. Keep going ahead till you find other 3 more marines behind a barricade. You'll need to hold that position until you kill every enemy! Don't advance through the barricade. After you kill every other enemy, you need to start counting. If you have less then 6 marines. Reset checkpoint. Also give every marine again forerunner weapons. Once you pass the barricade, and enter the field on the left a checkpoint will be saved. From that point you'll need to keep trying and trying. If you loose one marine, reset previous gamesave.. Remember, count 6 marines. Good luck.