1974 Duster door glass, need advice

When you changed out your glass did you have to remove the hardware from your window? I need to change the drivers side glass in my 74 duster. Bought a new amd glass and have no idea how to remove the existing hardware from the old window. Looks like a metal washer on each side with a plastic insert with a threaded stud. I see they sell new kits but they dont look the same.