We're excited to announce that we've fully migrated the Xbox Forums to their new home, here on the Microsoft Community forums!
As of today, going to forums.xbox.com will redirect you here to the Xbox area of the Community forums. We've moved all of your existing threads over so you can continue and start conversations with the new forums experience.
We sincerely appreciate the feedback you have provided over this transition and can't wait for you to check out the new Xbox Forums!
I take no credit for the list, merely reformatting it.
I also apologise for the message looking crowded, i did try to space it out :P
Pick-up: When you reach the Supermarket for the first time in Act 2, when you find your first staircase, circle around it and look underneath the stairs. Inside one of the shopping carts, you’ll find the orange skull. (Sometimes the skull
will appear in the sewers before reaching the Supermarket, so look carefully.)
Drop-off: Back in the sewers before entering the Supermarket, look for a large room filled with toxic waste with a ladder leading up to your left. Enter the door to the right after climbing the ladder, and look in the left most corner of
the room for a pile of skull. Follow the prompt to get your reward.
Pick-up: In Act II, during the quest “Uninvited Guests”, you’ll enter an apartment to fight some zombies. Past the kitchen, look inside a room with a glass cabinet. Smash the cabinet to get inside and take the skull. Make sure you don’t
complete this quest, or you won’t be able to return — the apartment also houses the drop-off point for the purple skull.
Drop-off: Returning to Act 1, run to a bunker in the southeastern corner of the map. You’ll find a man trapped by the zombies, kill the zombies and the man will lead you into the concrete chamber. Inside, you’ll find a manhole. Use it and
you’ll fast travel to another bunker. Inside the new bunker, find the door just right of the ladder up. Climb the ladder, grab an explosive barrel, and set it down next to the door right of the ladder. Shoot the explosive barrel to destroy the door, inside
the door, look for an cubby marked by a large blue pointer.
Pick-up: In Act 1, enter the bunker under the lighthouse. Enter through the manhole to go deeper, lookout for any zombies inside, and you’ll find the skull in the room.
Drop-off: On the east side of the island Resort, there’s a rocky mountain you can climb. This is tricky, you’ll have to awkwardly jump up the rocky cliffs, the spot where you can start climbing is marked with a few boards laying on the rocks
that serve as ramps. Keep jumping and climbing until you reach a small flag marked with a red pointer.
Pick-up: In Act 2, enter the sewers infront of the Church. Follow the winding path through the sewers until you reach two circular passages and a ladder. Climb the ladder up, and walk around the catwalk towards a makeshift hide-out along
the concrete ledge. Look near the mattress and at the altar of skulls, you only need the purple one.
Drop-off: Still in Act 2, during the mission “Uninvited Guests”, enter the apartment and walk into the kitchen were a stove with one lit burner is located. Place the skull on the marked stove to get your reward.
Pick-up: At the Gas Station in Act 1, in the southwest corner of the map. Near the Gas Station, you’ll see a small rocky hill just right of the Station. Check the southeastern slope of the mountain for a rocky passage up, partially concealed
by bushes. Up the ramp, you’ll find a toolbox with the skull inside.
Drop-off: In Act 2, back in the Supermarket, look for an aisle of teddy bears, lit up by a flashlight. One of these teddy bears will prompt you to deposit the skull.