All currently available CleanJuice are tool free, drop in, no soldering mods. That is the way we try and keep them for all consoles.
Buy a USB-C hole battery cover (or make your own) and drop in the CleanJuice to the original console. That's it.
For the GBA if you are not using one of our Prestige shells, you need to trim the bottom and side plastic tab from your battery compartment for the CleanJuice to fit in.
Source: RetroSix Knowledge Base