driver side glass replacement W124
 

Hello, can someone please tell me how do you stick in the new driver side glass in the older W124 (mine is 1987 260E). A while ago, the driver side glass was broken (vandals). Anyway, finally got around to fixing it, I removed the door trim and stuffs, so I rolled the thing down and removed the slider pieces where the old glass was glued to. Now I looked at it and can't figure out how you are going to stick the replacement glass into the door. The replacement glass was picked up at the local junk yard and it looks like its glued solidly to the rubber boots and sits tightly inside the slider aluminium piece. Are you suppose to separate the two somehow? TIA