It is some time ago, but I will try:

first you remove the fixing screws of the glass panel, you might have to tilt it to get to the screws. If I remember well, there are 6 screws for this action.

Then remove the screws holding the roof mechanism, I believe 4 or 6 in the front part (black) and another 6 in the metal rails.

Next step is to remove the sliding mechanism carefully out of the roof forward (up), just over the roof. Cover the roof paintwork!!

Try to keep this rails "system" in 1 piece, it will enlighten the putting back.

Do whatever you need to do to the inside of the roof cavity.

Put the sun roof back in reverse order.
Remember that the back end of the sliding rails need to fit in a metal fixing in the roof cavity. I couldn't get my roof back in and it took me quit some time to figure out what was wrong, and after that it took even more time to get the rails in the right position

Also take care in putting back the sunlight cover in the right position, if not placed correctly, it might prevent the roof from sliding good.

I think this is all.

Cheers.