Hey! If i’m understanding this correctly you could go to the image press edit on said image, scroll down a bit until you get to the section ‘add character’, add you sona, delete the image from the adopt character!! Lmk if this helps or not!^^
I got an adopt that I want to use the design for an existing character(particularly one of my sonas) but I dont want to have to reupload images and reenter credentials to the existing character if possible