AI does not hate you, nor does it like you, but you're made out of atoms it can use for something else. Given an AI that maximizes for some metric (dumb example: an AI that wants to make the most paperclips in existence), it will certainly develop various convergent properties such as: self-preservation that won't let you turn it off, a will to improve itself to make even more paperclips, ambitious resource acquisition by any and all means to make even more paperclips, etc... (see instrumental convergence for more details).

As for how it can kill us if it wanted to, or if we got in the way, or if we turn out to be more useful dead than alive: Hack nuclear launch facilities, political manipulation, infrastructure sabotage, key figure assasination, protein folding to create a deadly virus or nanomachine, etc....

Killing humanity is not hard for an ASI. But do not panic, just spread the word that building strong AI might be unwise when unprepared, and be ready to be pushed back by blind optimists that believe all of these problems will disappear magically at some point along the way to ASI.