If you bought the official Metal Gear Solid V: The Phantom Pain strategy guide by Piggyback, you probably noticed it did not include a guide to the final story mission (46). This was done to prevent spoilers. Now, you can download these missing ‘pages’ from the Piggyback site. To open the files you have to enter a password, which can be found in the guide itself: it is the first word on page 304.
In addition, Piggyback also lists the requirements to unlock the Nuclear Armament Event, which were previously revealed by the Famitsu Complete Guide a few days ago.
Source: Piggyback, via metalgearsolid.be