The PDF download includes 31 pages of pictures with step by step details, and a material list.
The crane used a bicycle crank to turn the crane in either direction. The hand crank allows kids to connect the hook to something and pick it up. The hand crank has a magnetic slip system that can be turned on and off with a screw driver so you can limit the amount of weight that the hook can pick up.
This is a fairly complicated build so if you are up for the challenge you will have one happy kid.
Note that this is a mechanical device and your child should be supervised on it at all times. This includes the use of a short piece of rope.