The Tempest voice coil connectors has 2 sets of spades on each terminal, so, simply connect one set of spade connectors from the first voice coil to the other set of spade connectors on the second voice coil (plus to plus, minus to minus). Then connect the cable from the amp to the spare spade connectors on the first voice coil terminals only to achieve a 4 ohm load.
Or you can do what I did, which is use a Dual-Input Terminal cup and simply did the bridging/paralleling at the terminal cup with the metal bridgej strips, and just ran cables from the cup to each set of voice coil terminals (which gave me connection flexibility without having to rewire the driver terminal connections inside the sub):
http://www.patcave.com/sunosub2/117-3919.jpg
http://www.patcave.com/sunosub2/118-3921.jpg
http://www.patcave.com/sunosub2/119-4363.jpg
http://www.patcave.com/sunosub2/120-4364.jpg
And here's my construction page of one of my Sunosubs:
http://www.io.com/~patman/sunosub2.html