MAN TGL folded middle seat, how to move upright

Potentially a weird one, and feel free to laugh at my ineptitude, but here goes.

I’ve been doing some agency work for a company, running midnight shifts to the depot before waiting a while and heading home.

The company’s got these new MANs with a foldable middle seat, but the ■■■■ thing seems to be stuck in the folded down position.
Does anyone know how to lift this thing back up, i’m 6ft4 and stuck in the cabs at the depot for 2 hours at a time with nowhere to put my feet, any help is appreciated.