After you receive your toy at home, the next thing you need to do is to open the seal of the box. Unfold it and take out all the parts of the motor building toy along with the user manual. Cut the pieces from snap-together and separate all the pieces. Then you need to polish the sides to make them smooth.  Else your kid might cut their fingers while using it. And try to fit them with your hand to make sure they fit well before you glue on them. You can choose to add them with glue or liquid cement. Make the assemble with the manuals. And you are done with assembling!