Check out my blog in a post dated 11/29/15.
If you want more pictures let me know so I can post them.
What model is your Ward? Eastcoast has a flat nosed bus (I think it is a Senator) I have a dog nosed bus. It is a Volunteer. His ceiling panels were different than mine.
His ceiling panels did not go all the way to the windows. There was an angled valence that covered the gap between the too of the windows and the ceiling panel. My ceiling panels went all the way to the window. That valence on my bus hid all the wires, lights, and speakers. It was attached to the ceiling panels.
I have a 91 Ward. I assume they are similar if not the same as yours .
I don't think removing the ceiling panels is going to help you. On my bus, there is a lip that wraps under the end of the ceiling panels. It goes the length of the bus. The lip starts against the outside skin, then it comes towards the center of the bus on top of the windows, drops down about an inch and then wraps around the bottom of the ceiling panel, then back up. The rivets go through the front of the lip, the ceiling panel, then the back of the lip. That lip, or hem, is welded in place.
I can't tell you how to the get the windows out, but if your bus is like mine, taking the ceiling panels down will not help.
Let me know if you want more pictures that show anything in detail.
(24 rivets above each window) X (11 windows) X (2 sides of the bus) = 11 cutoff wheels + (2 sore arms X 6 hours)