I am getting pretty good at this one.
Unlock the catch and do the usual press button thing. The windows will drop and the seats will move.
You then get a click and nothing else happens. Get out of the car and lift the back of the roof, its quite stiff so you can give it some force. Then get back into the car and press the button again. It should now work. You may have to help it a few times during the procedure.
Basically it needs greasing and regular use. Mine was clogged with muck, all this dust in the air doesnt help.
If this doesnt work let me know and we can try something else.