It's going to be four or more screws, some may be hidden under plastic tabs you must pry up. On some scanners some of the screws are hidden under where the hinges go in.
I see 8 screws on the top part in this picture. 4 are around the hinges.
On the bottom I see 2 screws and 2 plastic tabs. The plastic tabs are precisely aligned with the screws so there's a good chance there are screws underneath them.
I strongly suspect the glass on Epson flatbed scanners is nothing really special. It definitely isn't AN, it doesn't seem to have any special coatings and it scratches just as easily as regular float glass. I'd be strongly inclined to take any old piece of float glass, cut to size and put it in there; see how it goes.
Sorry, I thought you were just intending to clean it, misread. Although if your problem is stuff on the glass it might work better for you then trying to find a new piece. Why are you looking to replace it?
I have no problem ordering a new piece of any glass really. Thought maybe this kind of super truevue glass could be optimal. But maybe just white glass. I just cant afford too much down time on the scanner so im trying to be as efficient as possible. The glass seems to be glued in somehow.
Good reason! If it's glued, you might have to pry it up from the edges, once done remove the old sealant, and then apply new sealant to the new glass. Apologies that I don't know anything more specific about it.