Repair of bottom window sash/rail

I have 2 side lights on either side of my front door. One side is fogging between the double pane glass. I know this seal is probably gone. How do you fix this if the side light is part of the whole door. I've removed the modeling around the skylight and there aren't any screws to remove the panel which is why I assumed it is one whole piece along with the door and other side light. Is there any way to replace the glass? I've been told by Home Depot and another store that sells doors the whole door and both side lights need to be replaced. Can a glazier replace the glass? (There is no brand name on the door that I can see)

Hello all, What is the easiest way to hang interior doors? Last night my brother and I hung 3 or 4 doors at the house he is building. I've hung doors before but was just wondering if there are a few tips to making it easier. We did it the way my brother wanted to do it which is this: Slide door into opening(these were double pre-hung doors, not singles). He then plumbed one of the jambs and screwed it tight. He then plumbed the other side and screwed it tight. All the while we're doing this we're checking to make sure gaps and everything are 'even'. It was kind of a pain as the doors kept rubbing, or they wouldn't close all the way cuz something was 'pinched'. I don't know what was making it happen, but a few times the door would be hitting the hinge-side door stop(don't know if thats the right name, but it would be 'pinched' by the piece of wood that stops the door from going 'thru' the frame).We got them all done, but as I said it seems it should have been easier. One problem was the rough openings were BARELY big enough to get the doors in. I'm not sure what standard is, but I think he made his rough openings 2 inches bigger. So, does anyone have advice, as we have more to hang? I always thought you leveled the top jamb and then squared up the side jambs(by just measuring the diagonals) and shimmed accordingly. Thanks for any advice..... Ron