How can I unclog the defrost drain in my refrigerator?

Unclogging the frozen defrost drain in a residential refrigerator requires a careful manual cleaning process to restore proper water drainage. First, unplug the refrigerator from the wall outlet for safety, open the freezer compartment, and remove all food items, shelves, and the lower rear interior back panel to expose the frozen drain trough beneath the evaporator coils. Second, use a hair dryer on a warm setting or squirt warm water using a turkey baster down the drain hole to melt any solid ice plug. Third, gently push a flexible nylon pipe cleaner or a piece of stiff wire down the opening to sweep away trapped food particles. You can troubleshoot drainage flow easily. You can verify that your unclogging procedure was successful when pouring warm water into the drain trough results in smooth flow into the bottom evaporation pan.