What do I need to pirate 3DS games?

Is it possible to pirate any of the 6th generation Pokemon games? I heard you can do it by using Gateway, or Sky3ds? And what's this about downgrading your system? And do I have to buy a flashcart to do this, or can I play through Homebrew?

Sorry for all the questions. I've never done anything like this before.

Anyways, what do I need and how do I do it?