Monowiper wont go down (w124)
 

Once you get the monowiper on a w124 up how does it come down?
I dont want to brake it.

Push it down.

If it's stiff, spray some lube on the spring/cam area underneath.

I found that if you pull back on it and let it go it will spring back into place. I had a 124 and had the same problem and could not figure it out. This worked :)

Mine sticks up when I check the blade for damage, I'll have to try that trick and spray the hell out of the spring in there to loosen it up

It will go back down onto the glass if you simply push. It takes a pretty good push; I went through the same worries when I first pulled mine up to clean underneath, thought it was gonna break. I finally took courage, pushed hard, and it went back down. I'm used to it now but the first time is a little frightening.