How to remove glass

Hi, I'm new to the restoration scene. My son and I have a 1940 Windsor that has become our joint project car. Right now were trying to figure out how to remove the passanger door glass and get a new one cut. Question is how is it held in the lift track ? Can't really see anything that holds it and it seems like it's set in a rubber(?) channel.
Any help would be great.

bob
Author: bobE40