Use FTPiiU alongside a FTP Client (FileZilla for instance) connect both WiiU and server client to the same internet conexion. Enter the IP 192.168... and the port (*ip*:*port*) ex: 192.168.2.456:21 and while being on the ftpiiu blackscreen establish conexion

Once it is connected search for storage_mlc if your game is stored on the nand or storage_usb if it is on the current plugged in Hard Drive. then go to "usr\save\00050000\1018dd00\user\*username*" and change both thumbnail0.tnl and thumbnail1.tnl

Keep in mind that the title ID varies but as long as i know EUROPE is "dc" and USA is "dd". Also the thumbnails are meant to be smaller than 50kB if i remember correctly

If you dont know what user is the one with the level to edit go to: "storage_mlc\usr\save\system\act" and go through all account.dat downloading them and accessing them via notepad, vsc or text editor. Once you recognise the email and/or PNID remember the user ID(the folder name)

Psycrow used to have a tool for this but i couldnt find it. you can also use this hack to access other level thumbnails, subworlds, overworlds and sfx and literally overwrite your levels.

Here's an example i made of what i like to call "thumbnail overwritting" but using other level thumbnails

The Guy With The Super Leaf Basically Said: "ToDaY i'M gOnInG tO dRiNk 'Super Leaf'"

is it even allowed???

@OMARTHA as far as i know it is. there are plenty of levels that uses them. Clearly impossible levels are the thing forbidden to upload

Oh ok thanks for telling!

I now have figured out you need a JPEG img file 1x1 under/or 50kB aswell as a python code to convert it to TNL

the Git repository i am going to use is: https://gist.github.com/leuldereje/6f7d7e1556a0a103d60f27312f4aeff7