Ok Guys don't expect to do this on your first try, but this is the best technique to doing this.

GOOD LUCK!

-Stab the guy in the toilet.

-Pull out pistol and shoot the guy directly in front of you.

-Run forward and throw a stun grenade into the room and hide behind door.

-Run in with your SMG armed mowing down the people on your way.

-Be careful of the guy on the left as you go through the door sometimes he doesnt come into the room.

-Go left and throw a stun grenade then run forward and lay down behind the board and spray at it killing this rooms enemies.

-Head up the stairs killing anyone on the way and head left.

-Throw a Stun grenade again then head in and kill the guards in this room.

-Throw a stun grenade into the next room and mow down the people in front of you with smg.

-Be careful of the guy on the left behind the seats.

-Run down the hall pull out your handgun.

-Shoot the guy in the head.

Mile High Club Achievement unlocked.