Stephen tries his hand at modding the Wii U to try and access the final worlds in Super Mario 3D World without collecting every remaining collectible themselves, so that they can easily jump into recording the game with Alex and Hayley.
His plan is to mod the console so that he can download someone else's save file where the final worlds are unlocked but hasn't been played. Of course, things could go badly, so he's even acquired a spare Wii U from Player's Choice just to mod it.
He basically gets the Wii U to download some custom firmware called Haxchi and then runs the WUP installer to install the Homebrew Installer. He then installs Super Mario 3D World and plays a level to create a save file, which he then replaces with someone else's. Simply put, he succeeds!
With the Wii U modded, he can now load up custom levels for games if he wants! In the future, he plans to the Wii part of it as well so it can load up GameCube ISOs, which may be useful for their GameCube Extra Life event in November. But for now, they're just going to use it to finish off their Super Mario 3D World LP.