Steam
Almost every doctor will recommend steam inhalations, that will loosen the mucus and help you cough/blow it out. To inhale steam, you can make use of a vaporizer; use it twice a day for better results. Alternatively, taking a hot shower also works. However, if you feel too ill to have a shower, then pour some hot water in a large vessel, and bend over it. Cover your head and the pan with a towel to create a 'steam room' environment, and gently breathe in the steam. Do not be too close to the vessel or you might get a steam burn.