This video goes over the most up to date method of modding your SNES or NES Classic using Hakchi2 CE.
In the video I mention you can currently purchase refurbished units from Nintendo. Here are the links:
SNES Classic: https://store.nintendo.com/catalog/product/view/id/29575/s/super-nes-classic-edition-refurbished/
NES Classic: https://store.nintendo.com/catalog/product/view/id/27448/s/nes-classic-edition-refurbished/
Download Link for Hakchi:https://github.com/TeamShinkansen/Hakchi2-CE/releases