Toss in the wash with cold water. Air dry. Boom.
Not made for kids
"My daughter couldn't walk more than 10 steps in these before she was in pain. These aren't built for how kids actually move, a child's foot needs room to flex and run, not a stiff, adult-shaped shoe scaled down. I ended up throwing away both pairs rather than donating them, because I didn't want to pass that pain on to another kid. Please rethink how you design kids' shoes. Kids need to be free to move."