subwoofer connect question

I would like to integrate my Rythmik L12 subwoofer to my Yamaha RX-770 receiver.  the Yamaha has pre-out/main in with left & right rca's connected with jumpers.  would I just use the left & right pre-out to the subwoofer left & right rca's in? if so should I then take a jumper and place it in the left & right of the main in on the Yamaha?
Definitely, DO NOT put a jumper between the left and right of the main in.

Remove the left and right jumpers, then get 2 (one for left and one for right) RCA Y adapters like this (2 male to one female)

Use one adapter for each channel connecting the pre-out/main in. This just replaces the jumper that was removed giving a spare female connection for each channel. Then connect that spare L&R to the subwoofer’s L&R RCA input.