This is harder to describe that do.

The piece that is attached to the glass, stays on the glass.

There is a little retainer clip in the slider assembly that rides up and down the rail. Once that is removed the slider can be moved side to side on the window piece. It can be moved enough sideways to free it from the glass.

It is shown in FSM job 72-181. I had to do the job on my W210 and it looks similar. I found a tutorial on YouTube.

Comparing the W124 mechanism to the W210 is like comparing a Rolex to a watch from the dollar store. No kidding.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech