Converting my religion. (not to hindu/muslim/christian etc)

HI,

I  newbie here. I do not know anything about legal formalities and laws etc. So be kind.

My problem is peculiar. I am a Hindu from Goa. So I believe I am covered by the Portuguese uniform civil code or something and not the hindu law.

I want to change my religion to Shintoism ( Japanese ). And unlike other religions Shintoism is natural, you dont get baptized etc or change names .

So if I want to legally change my religion to say Shinto or Taoism and register it as such, what do I do?