There's no official place you go to to change your religion.
Religion is your philosophy of life.
Once you learn about Hinduism and know that what's you really believe in, you leave your past religion behind you.
I mean, you can go to your face book page and change it there...but other than that, it's more of an internal thing.
It sounds like you've been playing too much video games. You don't go anywhere to change your religion. You might want to stop going to certain places, like mass.
If you want to be Hindu, sit cross-legged on the floor and meditate to decide where you should go. It Inst really a strict religion.
If you really are Catholic, first you need to learn more about the Catholic faith. You can't reject something you don't know much about, and perhaps that is your situation.
Only Jesus Christ is the Savior of the world, and he established the Catholic Church. Please don't abandon the truth.