How Do I Get The Zombie Loadout?

According to this website, there are a number of things you must do to unlock everything:

• Zombie Gloves – Survive 50 rounds on any of the maps in Tier 1
• Zombie Kneepads – Survive 50 rounds on any of the maps in Tier 1
• Zombie Exo – Survive 75 rounds on any of the maps in Tier 2
• Zombie Boots – Survive 75 rounds on any of the maps in Tier 2
• Zombie Pants – Survive 100 rounds on any of the maps in Tier 3
• Zombie Loadout (Chest) – Max out the Armor stat (level 10) at the Armor Exo Station
• Zombie Helmet – Max out the Weapon Proficiency stat (level 10) at the Weapon Exo Station
• Zombie Shirt – Survive at least one round on all Exo Survival maps

Lastly to unlock the skin:

To unlock the Zombie Skin, you need to complete the secret zombie round in Exo Survival