I posted the same question a few months ago when I was working on the windows of a couple of Kato SD40s. On the SD40s the cab windows that face forward and rearward form somewhat of a latch that you depress with a tooth pick and at the same time you kind of giggle it around then the glass will pop out when it finally feels like it. It's tricky but just keep at it. that photo looks very similar to the Lifelike sw9/12 that I did too, the previous poster is correct in my case as well, the middle set or side windows keep the others in place.
I also found that the slightest amount of over spray in the coupler / pilot recces made the factory couplers bind every so slightly just enough to cause derailments through switches, wound up having to install MTL 2004
Good luck
Mario