Airsoft Tech provides a step-by-step guide on how to paint an airsoft replica with a "worn-out" or weathered effect. The process involves using specific spray paints, proper preparation with masking tape, and a unique nozzle for a diffused spray. After applying the base coat and additional colors, he explains a distressing technique using acetone or isopropyl alcohol to realistically wear the paint off, focusing on areas that would naturally show wear and tear on a real firearm. They advise against using sandpaper to avoid damaging the replica.