You would need to buy one of the games related to one of the many exploits. I suggest Smash Bros becuase it is not only a good game, but has the most reliable exploit: Stack Smash. By overflowing a data stack in the save file, the system crashes and allows for unsigned software to run. Other than that, all you need is an SD card and a PC with an SD reader. Tutorials are readily available online and very simple to follow.