L --> Left high
SL --> Left low
R --> Right high
SR --> Right low
C --> Center
SBR --> Surround Right
SBL --> Surround Left

Use Outlaw (or some other brand) Y-connectors to from the L and R outputs of the pre-amp to the extra channels on the amp.

I doubt it will make any difference in the sound, but that's how you'd do it. Don't forget to remove the bridging clips from the Maggies.

Cheers,