I used a wedge in addition to pulling down. Slip the wedge in and push sideways until you find a clip and twist while pulling down. They pop out easier this way IMO. I thought it was harder to get all the clips back in than to take them out. My sunroof is already manual, so good luck with the rest of the removal.
You probably already saw this but ...
http://www.peachparts.com/Wikka/W123SunRoof