New cords for old, and the golden rule

Episode of Series “Electricity Safety”. Do not keep old damaged electrical cords, and never try to repair them. Common causes of accidents are frayed cords, and badly repaired cords, broken plugs, and two cord flexes used instead of three cord flexes. Once insulation becomes worn or damaged wires are exposed which may cause shocks. Hows correct way of wiring new plugs and recommends that it is a job for an expert.