The first step would be to avoid the person who is irritating you, but if the situation is getting on your nerves, then you have to take few action, but do not get out of the way in urge to find a solution you might make the situation far more worse.
If your co worker is making your life a living hell, then start solving this issue with politeness. Whenever he tries to pin point you or tries to involve into your work, acknowledge his help and thank him. If you start arguing on the very first moment you might place yourself in the bad books.
If ignoring the bossiness does not work, then listen to your coworker and do whatever you think is good.
The second last option to get yourself out of the misery is by explaining your coworker with politeness that you appreciate his concern, but his conduct is affecting your official work negatively. Probably your colleague is not aware of the fact that his attitude is quite disturbing.
When the bossiness is getting out of control and you feel that it is heavily affecting your work, then the time comes when your actual boss has to look upon this issue. Instead of sharing it with someone else directly have a meeting with your boss explain the problem and don’t forget to mention that it is affecting your work, your boss will definitely find an appropriate solution.
If the respective person is your actual boss, then you have no other way out accept for barring him until you find another better opportunity, because he is the one for whom you are working, if he finds your attitude awkward your boss might fire you.