Yes, the glass is easy to replace.
To lube the window pivots, remove the inner door trim (the painted trim that surrounds the vent and door glass). You'll then see where the vent is attached at the base...it's usually rusty so spray it with some good lube and slowly work it back and forth. It should free up.
You can also loosen the bolt at the bottom of the post (you might have to pull the door panel back a bit). Loosening the bolt allows the vent frame to swing more easily.
Hope this helps!
