removing old 1960s secondary glazing [to clean it]

[boarcity]

View attachment 5468 any of you done it? im asking cos last week i was asked to remove some and couldnt get it to come out. it was the sash window sort that has a thin plastic frame surround with small white plastic sliders [thumbnail size] that you 1st remove then in theory this allows the glass to move across a tad then the pane pops out. Only in this case the glass would not slide across even after removing the sliders

its a long shot but i wondered if anyone knew of some extra knack /dodge/hidden clip that i dont know about

 

[TolishAPurd]

I've never removed them boar but I have cleaned a few. I've cleaned them with help from the customer. Its a bit of a krypton factor puzzle and always a laugh. One side from the ladder outside, and the other obviously inside and you just have to open the sash windows while they open the secondary glazing with lots of switching about until you get all the panels. If the customer is the moody aloof sort then don't bother as it will need there help and a sense of humour. Because it hasn't been touched for a decade it has the wow factor when its done.