The upper two pieces in your first pic go underneath the vertical center bar and over the two halves of the windshield trim. They are held in place by the screws going thru the center bar trim and into the external center bar, which has female threads in it. I don't recognize the lower piece in your first pic. Unfortunately the FAM illustrates the 54 single piece windshield, so no help there.
That center bar that''s welded in place doesn't get removed. The holes in it line up with the outer and inner trim pieces.
