I have copd and need to clear phlegm from throat. what is the best method with which to do this?

Don't smoke: Quitting smoking is the best thing you can do to decrease sputum production. Using anti-inflammatory medications such as advair or symbicort (budesonide and formoterol) can also help in some cases as can treating any and all infections early.

Medicines can help: The phlegm that you have is probably a consequence of the copd. It is always good to get it out. Medications like Mucinex (guaifenesin) can help with this, as can nebulized medicines like albuterol/ipratroprium.