Assassin's Creed Unity - Stealth Play "Moving Mirabeau" Co-op Mission (Solo) Edward's Outfit

Mission: Moving Mirabeau Co-op Mission (Solo)
Mirabeau is publicly disgraced, and the Templars want the Assassins to go down with their former leader. Retrieve Mirabeau's relics from the Assassin crypt under the Pantheon.
Outfit: Edward Kenway's Master Assassin Outfit
Armor:
- Legendary Phantom Hood
- Improved Prowler Coat
- Legendary Military Bracers
- Legendary Military Belt
- Legendary Phantom Breeches
Weapon: Sword of Eden, Upgraded Gold Plated Pistol

[@SamCheung2013]

How do you unlock this mission?