To be able to kill somebody

Could happen. Only real way to train is by punching the wall until it breaks. Then punch a harder wall. Then punch rocks. Basically its punching random hard objects until you (
a) wear yourself out and give up,
(b) break your hand to the point of amputation or
(c) actually go through with it and kill dudes with one punch.

Then probably the police'll get hold of this info and lock you up out of fear. Or some crime syndicate takes you in as a bodyguard. Personally I'd go for the latter.

Put something sharp between your fist.
Maybe. That will do.

Stop endorsing murder!!! DX

go to mexico an just shoot someone lol

well..punch the throat(without anything sharp) is enough..I think... :3

punch the solar plexus. or try to use a backhand chop into his neck then crush his trachea.

you could punch a baby i guess...they seem to go down easy

kill someone while your drunk?