Hubert, when I have refinished interiors on my cars, I use the Aircraft Paint Stripper ONLY on the metal doors. As previously stated, the Aircraft Stripper will ruin the fiberglass panels and any vinyl parts. Use the Easy Off oven cleaner on the fiberglass pieces. Be patient, it will probably take 2,3,4 applications to get all the paint off depending how many layers of paint you are removing.
Easy Off Oven cleaner comes in yellow and blue cans. You must buy the yellow. The blue will not remove the paint at all.
Spray a good heavy coat of the oven cleaner on the interior panel and let it sit for quite a while. I would cover mine in plastic and let them sit over-night.
You do not want to use a wire brush, sand paper or any other abrasive on the panels, you will ruin the grain pattern. Once you have let the part soak in the oven cleaner for a long time, take the garden hose with a pressure nozzle and spray the oven cleaner off under high pressure. A soft-bristled dish cleaning brush (similar to what you would use to clean plates in your kitchen) can be used to help loosen the paint while washing off.
Now for painting once you have it stripped.
If you don't have access to a paint gun and want to do the work yourself, use SEM paint/dye products. They make a wide variety of colors. SEM covers great and my experience is it looks fantastic for years and years. When you buy the SEM paint, also buy either their vinyl or plastic prep, depending on the surface you are painting. The prep is really important to get the surface super clean for best results. I've even used SEM paint/dye on a headliner to get the color I wanted with excellent results.
https://www.semproducts.com/