You can use browserhax and old eshop downloader to get ironfall invasion 1.0 in order to setup ironhax. This is the most advanced thing you can safely try right now.
There are claims of multiple successful downgrades to exploitable versions, but is too unstable and risky right now without a proper hardmod. Your best bet is to try and setup ironhax for your 3ds and enjoy some homebrew emulators while the whole downgrade thing gets stable and safe to go into the cfw thing (couple or so of weeks, soon™).