Written tutorial is in the video description. Based off of @pongozilla tutorial

EDIT: Fuck, your name is spelled @pongozila. I mispelled it in the video credits.

 

Great question. By Simply running the Exploit again, When he loads those URLS in Spider, the URL Dumps Hex values into RAM, these values may/may not overwrite current Hex vals.
In other words your modifying the games running Code. EX: Mario's kart wheels are default, so changing the value at ID: 000000; to 1,2,3,4, etc; Will change the Current Accessory/Item.
Same go's for the Wii U.