Ercoupe Windows

I just replace the rear windows on my 415C. Next week I'll replace the slide-up windows but have a question. Most Ercoups have a cover on the top of the metal slider case that you remove to slide the windows up and out. The cover has two screws for replacement. My friend Steve has just that setup on his 415D. However, my 415C does not have it and I can't figure out how to get the slide windows out. Any help would be appreciated either here or by phone at
520-444-4390
Regards, Larry Ercoupe N93436 Tucson, Ax