Burstner bedroom step

Morning all.

We have a Burstner 728 with the step in the rear bed area that pulls out, locks in place, and is retained via a sprung plastic clip. The clip is recessed in the slide out section and is broken. I have a spare, but I need to get the whole lower section out to get to both retaining screws to remove and replace. 

Problem is all screws are hidden, and I can’t work out for the life of me how to do this….

Any of our finest minds have any ideas ? 😊

pics attached in case my description isn’t clear 👍🏻