To play as Meryl, first complete the three training modes. (Training, time and shooting.)Now save them and go on to complete the game once and save Meryl. You will now have a saved game appeared saying Dock:00.00. Play this game and complete it again with Meryl, this time finishing the game between the times of three hours thirty minutes and three hours thirty one minutes. This is very tricky, but bear in mind that animations don't consume game time. Now just play the file once more, but when you reach Sniper Wolf for the first time, let her kill you. Now when you press continue, you will be Meryl and see Snake being killed, but your voices are back to front! This will last until Ocelots torture.