Super Smash Bros. for Nintendo 3DS and Wii U: Add-on Content Smashes In!
Download and Install Wii U Games with USB Helper Launcher - CFWaifu
TUTORIAL] How to install DLC's on Wii U RedNand (IOSU) | GBAtemp.net - The Independent Video Game Community
Help, WUP GX2 Error: Not a game, game update, DLC, demo or version title (I'm using Haxchi, and downloaded the title from Wii U USB Helper into my SD Card using titlekeys.ovh) :
Download and Install Wii U Games with USB Helper Launcher - CFWaifu