Metal Gear Solid 3: Snake Eater HD Edition Tips

Easy boss defeat
The easy way that I find to defeat The Boss, is to wear Snow Camo and equip AP sensor.
Lie down and wait for her, then shoot her in the head with a Sniper.
And if you are running out of time, go near her, and when she tries to attack you, dodge her cqc attack's, and hit her, and she'll collapse, then shoot her with a shotgun or a more powerful weapon.