I had a similar accident happen in 2013 when the supervisor/watchman at my storage facility/tow yard decided to spin his wheels on a car near my trailer, threw a rock, and broke 1 pane of the bottom slider on my rear window. I went looking on the internet for auto glass repair shops in my area (Sacramento), and found a company that included "RV's" in their list of serviced vehicles. They came out, measured and removed the remains of the broken tinted safety glass pane, went back to their shop and made a replacement matching safety glass pane, came back to the site and were able to install the new pane without removing the frame. The storage guy shelled out about $200 for this.