It's been awhile since I've removed mine, but I recall that you probably need to "push" the whole sunroof panel forward before the tabs on the front will allow it to swing down properly. Kind of a "wiggle" thing, but it will eventually seat itself correctly.
A trick that helps (if you haven't already discovered it) is to open the hatch, lower the tailgate, and then lower the hatch to the closed positions, so that you have a place to stand while performing this awkward feat.
Thanks. Still having trouble. It appears someone in the family tried to replace wiht the wind break up. Do you know if the prongs on the skylight that go into the front housing are curved at the point or flat?