This method worked for me. I had played no other missions on LASO prior to attempting this achievement.
Load up any mission. From the
Main Menu go
Campaigns - Halo# - Missions. The only missions that will
not give you credit for this achievement are
Halo 2: The Heretic and
The Armory, Halo 3: The Arrival, and
Halo 4: Prologue and
Epilogue.
I personally think
Halo 4: Shutdown is the easiest to beat LASO. So I set the mission to
Shutdown, no change to options, Legendary difficulty, and I clicked on every skull, which for
Halo 4 is 13. Here are a list of the skulls that need to be on for each game to comply with the LASO playlist rules specific to the Master Chief Collection, as some games don't actually want you to literally have all skulls on:
Halo: CE Anniversary LASO PlaylistBlack Eye
Boom
Eye Patch
Famine
Fog
Foreign
Grunt Birthday Party
Grunt Funeral
Iron
Malfunction
Mythic
Recession
Halo 2 Anniversary LASO Playlist:Anger
Assassins
Black Eye
Blind
Catch
Famine
Ghost
Grunt Birthday Party
Iron
IWHBYD
Mythic
Sputnik
That’s Just…Wrong
Thunderstorm
Halo 3 LASO Playlist:Black Eye
Blind
Catch
Cowbell
Famine
Fog
Grunt Birthday Party
Iron
IWHBYD
Mythic
Thunderstorm
Tilt
Tough Luck
Halo 4 LASO Playlist:Black Eye
Blind
Catch
Cowbell
Famine
Fog
Grunt Birthday Party
Iron
IWHBYD
Mythic
Thunderstorm
Tilt
Tough Luck
Now because the Iron Skull sucks, and will reset you to the start of the level when playing solo if you die, and there is a possibility to die in this mission like any other, I signed in a guest on a second controller and just let it sit idle. This will allow you to have those all important checkpoints throughout the short mission.
Now the method for running
Shutdown on LASO is the same as speed running it. I would recommend learning from the Halo 4 master
ProAceJoker at this link. He starts the tutorial for
Shutdown at about 01:09:12:
If you know the techniques already then here's a quick video of me demonstrating my method for getting this achievement below.
Good luck!