Glenn,
Connect the positive from J2 to the positive of one speaker wire, the negative of J2 to the negative of the same speaker wire and connect the other ends of the speaker cable in the same fashion to either J4 or J5, it does not matter which.
Example:
J2+ >-----------> J4+
J2- >-----------> J4-
J3+ >-----------> J5+
J3- >-----------> J5-
You can connect the other speaker cable in the same manner from J3 to which ever of J4/J5 you didn't use for the first cable.
Use the high gain setting and let em cook for a couple of days. Assuming you can live without them that long...
Mike G.