Ok , you need to open the roof Manually and the boot flap, fold the roof into the boot space,you will then see a row of pozzy drive screws which are along the front edge of the inside of the roof. Under these screws is the motor and switch , remove the screws and the plastic cover. Now you can see the motor with 2 arms on it.First switch ignition on and hold the open roof button. What happens is the gear in the center of the motor which drives the arms to release the catches sometimes disengages (especially if you have put the manual tool in it) and does not drop back into its meshing position. If that does not work you have to take the motor off and the arms which are on a ball and socket configuration,turn the motor upside down and you will see the main mechanism (looks like a circle with cutouts at each end )whats happened is that circle has not turned far enough and hit the microswitch , so you need to hold the motor in your hand whilst someone presses the switch to the open roof position,you should see the circle mechanism move to its correct position,once that has happened put it all back together,reset the roof how i said before and all should be good.
I will pm you my mobile in case its all a bit much and i'll talk you through it, before doing all above get a torch and shine it up into where the manually key goes and see if you can see if gear has disengaged, i bet it has, its very common.