Goal

Put the six blocks into the box through the opening on the top, without breaking anything!

Solution

See the animated GIF for the solution.

Printing

A fairly small print, but you can scale it up by 50% if it is too tiny for your fingers.

Print the Lid in a transparent material, glue it using a tiny amount of CA glue (super-glue) to the top of the main Box, and glue the Box Frame above it.