Once you are of major age i.e. 18 years then it is for you to decide.there is no specific rule or law on this issue but if you are staying seperately from your parents even today then why do you need to take any such step ??
At the most, you can give an advertisement from your own side in newspaper stating that you have separated from your parents and you are abandoning all the social and blood ties and relationships with your parents and you are no longer connected to them and you do not want any of their property or money or any other thing during their life time and even after their death. This will serve your purpose.