To pass a radon test, ensure proper ventilation in your home by opening windows and doors for several hours before testing. Avoid using fireplaces or candles during the test period. Place the radon test kit in the lowest level of your home, away from windows and doors, and follow the instructions carefully. Close all windows and doors and leave the kit undisturbed for the recommended testing period, usually two to seven days. Seal the kit and return it to the lab for analysis. If the results exceed the recommended safe levels, consult with a qualified radon professional to discuss mitigation options.