Jennifer why did you turn it the other way up,I like being able to have the blind part up to let light in without folk being able to see in.
Anyway,job done with thanks to Mick from Swift.In my case all eight screws were there which meant using a cordless drill screw driver bit held in mole grips,and by feel only undo them quarter turn at a time (2 inch screws took a long time,they have not gone back in)
Getting the cord back on was still a little difficult but possible with the cassette flat.
So take care when opening or shutting the blinds because if the square window catch fastener is not straight it fouls the blind which tilts and lets the cord come off.