Removing scratches from plexiglass involves gluing and scrubbing the scratches, and then polishing them. Use school glue, a sponge, cotton swabs, scratch-removing polish and clean rags to complete this task. A paper sheet is also handy.
To glue and scrub the scratches, first prepare the glue by putting it on the paper sheet and allowing it to dry slightly. Soak a cotton swab with the glue, use the swab to apply the glue on the scratches, and let the glue sit on the surface for 60 minutes. Dampen the sponge with water, and scrub the surface with the sponge in a circular motion to sink the glue into the scratches and clear the surface of excess glue. Allow the surface to dry.
Once the scratches are dry, dab the polish over the surface with the cotton swab, taking care to mix the polish well before applying. As you continue dabbing, add more polish to the swab as needed until you cover the entire surface. After dabbing, sink the polish into the scratches by rubbing the surface with a clean rag in a circular motion. Allowing the polish to dry and clearing the polish from the surface by wiping with a clean rag completes the process. Be sure to change the rag once it becomes saturated with the polish to achieve a clean surface.