5907f556_ecrets_for_Xbox_360___GameFAQs__How_to_Unlock
[Unlockable] Sneaking Suit [How to Unlock] 
In Locker you put Major Raikov in (Second time you go to Groznjy Grad)
Metal Gear Solid HD Collection Cheats, Codes, and Secrets for Xbox 360 - GameFAQs