Our 2006 has instructions for manually working the slide on a sticker inside the cabinet door under the sink. Not sure if it's the same procedure, but I'll try to attach a picture of it to this message.
I'm not sure our concern is with the mechanism. Since our slide seems to be supported only in the middle, I'm more concerned with the floor of the slide bowing at the end(s) from the weight of the new seats, and the effect this might have on seals, operation, longevity, etc.
We measured the sag today. It was about half an inch, as best we could measure. It drooped another quarter inch when I sat on the end of the couch next to the driver's seat, farthest from the big track thing in the middle.
2006 Sunseeker 3100SS - "Heart Of Gold"