METAL GEAR SOLID 3: Snake Eater - Master Collection Version

In order to get this avhievement, you need to sneak up on a guard, grab them from behind and slit their throat. I would recommend doing this early in the game say in Dremichuj. The best way to sneak up on a guard is to wait in tall grass prone with camo and facepaint that puts you at 80% or above. This ensures that enemies won't spot you unless they trip over you. To sneak up on them, try using the d-pad as this causes Snake to move slowly and silently. Once you are in grab range behind an unsuspecting target, press and hold to grab them. Now that you have a knife at their throat, press to slit their throat. The achievement should pop within a few seconds.