Your friend’s symptoms are not something you would be able to deal with on your own. If, as you suspect, he is a psychopath, he would need some intensive help in the form of professional treatment. Many of the symptoms you mention point to this need.
As a friend, I would let him know you are there to help and that you care about his well being. If the friendship is solid, you may let him know that you would be willing to go with him to a psychiatrist or clinical psychologist. These professional people are good at offering tests and diagnosis that can be helpful in determining exactly what your friend needs.
A word of caution. You friend’s inability to have empathy, lack of concern of others, and desire to hurt someone may all also apply to you. Offer help, but also be mindful of your own wellbeing in the process.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral