Halo - Combat Evolved Easter Egg - The Famous Megg

Please follow the full steps given below to trigger Megg.

1-Start Halo
2-Start new campaign with legendary Difficulty and the first level i.e. Pillar of Autumn.
3-When the Intro is playing, press Esc to skip.
4-Then you will see yourself coming out of the cryo tube and when that ends, the guy will shout "Cmon lets get the hell out of here"
5-Ignore him.
6-Move forward a bit and turn 180 Degrees so now you are facing the cryo tube you came out of.
7-Run and jump over it until u get on its upper part.
8-Look right and you will see the shield charger.
9-JUMP over it and then JUMP over the
Platform(please JUMP over them, dont walk on them)
10-Now, move right until you hit the wall.
11-Turn around and move until u hit the other wall on the left side of the shield charger.
12-Dont get off the platform yet.
13-JUMP on the Yellow Cylinder.
14-Now, if you want to know if the Megg is going to work or not, you will see it now!
15-When you jump on the cylinder, the guy standing at the door will say "This way" and runs. Thats the key. If he says that and runs away and you are still on the cylinder, then congratulations, you have triggered the Megg and are almost done :)
16-When you hear the explosion and the music starts, jump on the platform again from the cylinder and walk to the other wall on the right side of the shield charger but dont hit it. Stay a little away from it and then jump off the platform and continue the game as u normally would.
17-When you get to the marine who is standing in front of a door blocking your way, and when you walk to him and it says "Chief! The Captain needs you on the bridge A.S.A.P. Better Follow me" , get ready to jump.
18-As you approach him and he just starts saying the above dialogue, jump over his head and move in the next room and then get to the bridge without following him or listening to all of his dialogue.
19-When you enter the bridge, dont get near Keyes
20-Stay at the sides of the bridge and move to the front where you will see the drivers.
21-Jump on them and fall down below them.
22-Turn around and you will see the ladder and a
message on how to use the ladder.
23-Get up and move to Keyes and let him give you the pistol.
24-Get out of the bridge and kill the 3 Grunts and grab the assault rifle.
25-Reload the rifle and move back in the bridge but dont go too much inside because you need to run back a.s.a.p too and you need to save time.
26-Take out pistol.
27-There will be a guy standing on the right side of the path that takes you to keyes.
28-Stand real close to him and aim at his head.
29-Then Meelee attack him with the pistol which will hit the pistol's butt right into his head and he will die.
30-Cortana will get mad.
31-QUICKLY take out rifle and get out of bridge but this time, get in the little area on the right other then going on left where you killed the grunts.
32-The door which is usually closed will open and 7 or 8 INVINCIBLE MARINES will be standing in there.
33-Just start firing.
34-I suggest moving a bit left and right while you
are holding down fire button so that you hit every marine.
35-This wont kill them, just slow them down.
36-You might run out of a clip.
37-Move right, take a little cover, reload and start the firing again.
38-By this time the Megg room will open which is behind the marines.
39-Keep firing and get the hell in the room and move futher near the end of the room.
40-The Marines will not follow you.
41-Move near the end of the room and look up.
42-You will see the Megg.
43-Now when you are finished you can get out and
get yourself killed, lol.

I am sure that if you follow the steps corretly, the megg will work no matter what. I will also post screenshots to help you.

Much credit to Boneho for the original discovery of this egg :)