Do i remove the two coutersunk screws both sides to get the cracked window out? It's a coupe with electric windows

 

Sorry I don't know about the 1957 specifically, but I have removed a number of power window parts. Be prepared that there's a strong spring on the regulator that when you unbolt things it may release with a bang. I believe you will have to either remove that channel from the glass or loosen the regulator so you can slide the wheel out of the channel. Take lots of pictures of how everything is assembled to help when you put it back together with the new glass.