Ripping Out Someone's Heart

[JCurwen3]

What would it take to rip someone's heart out of their chest (killing them, unless they have some exotic advantage) in RAW GURPS? I know the heart is normally -5 to hit, although this is probably more difficult than just hitting the heart, and involves targeting the area with a fist, breaking through the rib cage, finding the heart within, and ripping it out of the chest cavity. Since the fist generally does crushing damage, by RAW it doesn't seem like there'd be any wounding modifier, although in this instance the fist is acting more like an impaling weapon.

I know that to do this requires superhuman ST, so the next question would be: how much ST to do this to an average human?

Also, ignoring RAW, because it doesn't like insta-kill attacks and I'm less hostile to the idea of them, how much damage does the heart really need to "cripple" or destroy it? For instance, the eye takes HP/10 to be blinded, and double that to be destroyed. As a house rule, if I wanted to treat the heart in a similar manner, for the purposes of injury (including being ripped out), what would be a reasonably realistic way to do this technique then, and how much HP of injury could a heart withstand?