1) You could hit them with a stick. They wouldn’t like it and you might get some joy out of it. However, they are unlikely to become likeable just because you’ve beaten them up a bit.
2) Positive reinforcement tactics as seen in The Big Bang Theory and from Science. Whenever the person does something you like you reward them with say some chocolate. This should link the good behaviour with the treat and make them more likely to continue the good behaviours. However, the rewards need to be given quickly and often in order to reinforce the behaviour. This could be difficult if you are not always around the person. Perhaps, starting a positive reinforcement group to help to continue the rewards system.
3) Fight them, realise you are really quite similar, team up to destroy a bigger enemy as seen in Star Trek. Spock and Kirk hated each other and could not get on at all but after much, much fighting, they soon became the bestest of friends and fought together to destroy many space evils. However, if you fight in a public place you may just get into a lot of trouble before you can team up to destroy the bigger enemy. Also, you have to make sure that there is a bigger enemy in order to unite you.
4) Ignore them. Attempt to have absolutely nothing to do with them. Cut them out of your life. This works best when the person is voluntarily in your life. This is more difficult if the person is a work colleague or a neighbour.
5) Attempt to kill them with kindness. Everything they do, every horrible or dislikeable thing they do, just smile and be super overly friendly to them. Hopefully, this will lead to them realising that they are not getting you down and that when they act horribly they just look stupid. This is a long term method and may not lead to the person realising how sucky they are. However, it could lead to other people thinking you’re a really cool person and buying you chocolate.
6) Explain that they are acting inappropriately and that you really feel that they should stop it. Often the horrible person will not realise that what they have done is inappropriate. They may change. They may not but at least they know that you think they suck.
7) Dance to the music of Nsync. This always works.