How to strip strain from a fiberglass door?

To strip strain from a fiberglass door, start by cleaning the surface with a mild detergent and water to remove dirt and grime. Next, use a fine-grit sandpaper to gently sand the affected areas, which helps to smooth out any imperfections. After sanding, apply a fiberglass repair kit or resin to fill in any cracks or scratches, then sand again once it dries. Finally, finish by repainting or applying a sealant to restore the door's appearance and protect it from future damage.