Hello NEW 2015 Fuzion 345 owner

[Fuzion345]

Hello from SW Colorado. We just purchased a 2015 Fuzion Chrome 345.

Here is my first question:
There is a side piece attached to the master bed that is part of the Glide-a-bed System for the King suite.
The bed only has a queen matress and we can not figure out HOW to extend the side to accommodate a king mattress. Does anyone know how to work this thing?

Thanks for any ideas!