Create a folder that looks like this on your SD card:

SDHC (E:) > 0005000010144F00

(It must be that exact string of characters, and must be on the root of your card, i.e. not inside another folder.)

Restart Sm4shExplorer, and go to data > figther > FIGHTER_NAME > model > body to make sure the skin was successfully copied from Meteor. Click Project at the top, and then Build the mod. Click OK, Yes, all that good stuff. When it’s done that, it’ll ask you if you want it on your SD card.* Click Yes.

*If it doesn't, copy the patch folder from sm4shexplorer 0.07.1 > export > content into that folder you made on your SD card.

Stick the SD card in your Wii U. Boot the Wii U up and go to the web browser. Create a new bookmark by going to any webpage and tapping the bookmark button. Edit that bookmark and call it Loadiine, and have the URL be http://loadiine.ovh. (If you dumped your game and followed the EU steps, you should already have this bookmark! Just use the same one.)

Click the bookmark. It should say “Detected Firmware: 5.5.1” – under that, a drop-down menu and a check box. Tick the check box, and select from the drop-down “SDCafiine + Kernel.” Confirm your choice, and click the button next to the drop-down. It should do its thing, then send you back to the HOME Menu. Go right back into the browser, and back to the same website. It should then do another thing, and on the Gamepad you’ll see a coffee cup. Press A on the Gamepad.

After it boots you back to HOME a second time, just exit the menu, boot up Smash, and yay, you’re playing with mods! Every time you want to play with mods after turning off your Wii U, you’ll have to repeat these steps on your console. It’s a bit of a process, but it’s not too bad, especially if you manage to get it to automatically go to Loadiine when you load the internet browser (such as by closing the browser while on Loadiine's page and not running the exploit).