Using these Heroes of Goo Jit Zu toys is super easy! To activate the color transformation, just find the core (capsule) under Black Panther's chest and crush it. You'll see the amazing color change happen inside his body. You can also squeeze and stretch these heroes as much as you like. They're made of durable materials, so they can stretch up to three times their size and then go back to normal. When you're done playing, store them in a dry place. Avoid exposing them to sharp objects as it might damage the goo inside. That's all there is to it - have fun collecting and playing with these awesome Marvel heroes!