Child safety windows.
 

Hello I have an 83 Delta 4 door. I thought that an 83 would be before child windows but I am mistaken. They only go down halfway is there just like a rivet in the window track and stops him from going down how can you take that out to the window we'll go down all the way? Has anyone have this problem before? All responses greatly appreciated.
https://cimg2.ibsrv.net/gimg/oldsmob...0b8b0597b8.jpg