Make sure the safe is locked by pressing button B, the one on the right.
Turn the dial -- the Circuit Playground Express -- to the first position, in the case of our default code, this is to the left so the NeoPixels glow pink. Then press button A, the one on the left.
Now, turn it so the lights are white, and press the A button.
Finally, the moment we've been waiting for! -- turn the dial so it lights up orange and press the A button one last time. The lights will turn green -- success! -- and the lock will open. You're in!
Swing open your safe door, and now you can hide another valuable treasure within. Such as an undeveloped roll of 35mm film from the 1990's...
Close the door, press the B button and it will lock again.