Difficulty: Legendary
After your new shield gets tested in The Armory, Johnson will come down the elevator and wants you to come with him. Don't get on the elevator right away and instead wait until he says
"Would it help if i said please". That's your signal that you can enter the elevator. I had to wait about 2 minutes.
Get on the little transit with him and look in the direction you're headed. You can see the skull sitting on some boxes. Go to the right window in the front and
hold the Action/Reload Button and you will automatically pick up the skull once you are passing it.
The Armory1 -
0:10 - That's Just...Wrong Skull