1) Cut the heavier 7mm chain down to two lengths of 6".
2) Open all four of the jump ring and use two of them to attach each length of the heavier 7mm chain to each side of the Toggle Clasp. Close each of these jump rings and then attach each of the two remaining open jump rings to the free chain ends of the heavier 7mm chain.
3) Thread on all of the other lengths of chain between the two remaining open jump rings. Make sure to thread the lengths of chain in the same order on each of the open jump rings so as not to tangle the lengths of chain up in one another.
4) Close the two remaining jump rings