I found the earlier parts of the level to be tough, but not tougher than any other Veteran level. The hardest part is the battle in the news room. The problem is that the enemies will constantly spawn from the far side of the room and you'll never finish it.
What I did was immediately turn 90 degrees to the right when I entered the news room and run straight to that corner, taking cover behind the desk there. I took out the group that was emerging from the spawn room, then threw a flashbang towards it and ran there while the enemies were stunned. Once you enter the spawn room, the enemies stop spawning and my team killed the remaining enemies in a matter of seconds. One enemy did come after me in my hiding place, so just be aware that you are not completely safe. Once the enemies are dead, you just stroll to the end of the level and get your achievement.
tl:dr Enter news room, turn 90 degrees right, run forward to corner, turn 90 degrees left, flashbang, kill, run forward, 90 degrees right.
NOTE: I've been informed that "spawn hallway" might be more accurate than "spawn room". Either way, just get to the place where the enemies are pouring out of.