Recommended way to assemble - King

1. Slot a Partition C into each end of Partition A

2. Flip upside down

3. Slot another Partition A into the opposite end, to complete the outside of the grid

4. Slot the final Partition A into the middle of the grid
5. Flip upside down again

 

6. Slot the final two Partition C pieces into the middle, then flip upside down one last time