How do I access the rear drain holes on the 95 Celica sunroof --to clean them?

What is your question?

The front drain holes were easy to locate and clean (leaky sunroof) but I can't see the entrance to the rear drains as the view to them is blocked by the open window. Even on tilt mode, there is not room to see them. Where could I get a diagram of the drains? And if I have to take it to a shop, what sort should I take it to? Where do you find specialists in sunroof repair?