[Healeys] Removing Side Window glass

[Charlie Frazer]

I need to remove/replace the side window glass from the driver's door  
of a BJ8.
I've followed the shop manual instructions to the point of
"...release the  regulator arm from its guide channel in the glass  
frame."
How do you do this?
I've checked the archive and though the question appears there, the  
answer does not.
Thanks for your guidance.
Charlie Frazer
cfrazer at uoregon.edu