There are two Torx fasteners that hold the front latches of the glass top to the frame of the car. One of them was loose--and I could not see how to get access to it. There was insufficient clearance for any Torx tool that I could imagine to fit in there.
The trick is to remove the little pad by pressing it out from the top.
Then rotate the handle until the hole that the pad covers is lined up with the Torx that you otherwise can't reach.
Careful as you remove the pad. There are three little plastic prongs that hold it in place, and I think I broke one when popping it out. (And I'm sure it's a $50 part from Chevrolet.) It still stays in place, however.