If you can get the old panel off without disturbing the original brackets, then you can adapt the new panel to those brackets. The original wire comes up through a grommet in the roof. I couldn't get our panel out of the brackets after removing the attaching screws, so had to pull down the inside ceiling carpet, remove the screws to only one of the brackets, get the panel off, put bracket back on. I did not install a new
solar panel, only removed the old one to fix a seam leak under it. The original panels were only intended to keep the
battery up while the trailers sat on the rental lot. I did not reinstall the original panel.