Use a power sander with a low-grit sand paper to strip the old paint off the surface of your vehicle. Use a sanding block or just the sand paper to reach small or hard-to-get places.

Make the first pass with at least 100 grit, possibly even as low as 40 grit sandpaper. Coarser grits will remove the paint efficiently, but leave a very rough finish.

Make a second pass with finer sandpaper (200 grit), to reduce the scratches and smooth out the body.

Repeat the procedure with 400, 800, and 1500 grit sandpaper to make the car's surface super-smooth. Spend a good amount of time with each grit, as it will be much harder to remove the deep scratches down the line.

Wipe off the sanding dust occasionally to help speed the sanding process.