In a Microwave Oven
Place coarsely chopped chocolate into a microwave safe bowl. Microwave for 30 seconds, then stir well. Continue to microwave for 15 second intervals, stirring well after each interval, until smooth.
In a Double Boiler
Place coarsely chopped chocolate in the double boiler over hot, not boiling, water. Stir until smooth.
Please note: For best results, do not overheat the chocolate, and avoid introducing moisture. Both these conditions will ruin the chocolate.