How to get the Annual Acheivment In Halo 3

First, Round up 4 players that are decent and get the game started. Don't bother looking for the ghosts you have to backtrack from killing 343 Guilty Spark; when you first see the Grav Hammer flooded Brute, walk to your left with a BR and have your friends use their Fuel Rod Guns. Jump up on a rock and look to where you jumped down, Jump on top of the Snowbank and wail on them until you can run threw un-touched.

when you get far enough, go to the corner by the giant slant and wait for a checkpoint while you kill, get a Senetial Beam and kill the bigger ones like Stalkers, Flooded Brutes, Ect. Tip: DON'T USE THE FLAME THROWER! Try to stay in pairs and you'll get up top first try. if sombody has a low shield jump infront of them and melee the hell out of them.

When you get up top, get the auto turret, and jump on a piece of the ground that sticks up infront of the door, jump on to the door frame and throw it up there. now it's high enough to not die. get a plasma rifle and if you still have a rocket launcher, blow the hell out of them. Remember when your done up top, kill ur auto turret it will kill you after 343 Guilty spark dies.

When you get to Guilty Spark, keep on the door you got on, and don't jump at all. if you beat up Sgt. Johnson you have some lazers, use them up until Johnson hits him, take his laser and own Sparks. Now, insted of going on the Snowbank, turn Left and go down the up ramp, When you get down it, Use your flashlight on the ramp you walked down it has 4 Ghosts compacted into it, and remember Stay by the pillers when the grounds exploding, Don't hit the Flood Carriers or you'll flip.