Rear Seat Removal

[dfr]

I've only had the car a few days so it's all new to me. The rear quarter lights go down but not up so it sounds a like mechanical problem.
To get at them I must remove the casing over over them and before that the rear seats. The only information I could get was to remove the nuts below the seat squabs. The squabs lift but the backs remain fixed. How do I remove them please?
Frustratingly, there is link to just this subject on this site and it's the only one I've found that doesn't work.

[IanL]

Here you go: