Complete the appropriate form for your situation. If your passport was issued over a year ago, then you must use Form DS-82: Application for a U.S. Passport by Mail. If you received your passport less than a year ago, then you must complete Form DS-5504: Name Change, Data Correction, and Limited Passport Book Replacement. These forms request general information such as name and address, the nature of the change you are requesting, your Social Security number and an emergency contact.
Gather the documentation you need to support your requested change. If you are changing your name because of marriage, or other court order, you must provide an original or certified copy of your marriage certificate or the government-issued document evidencing your legal name change under federal or state law. For other corrections see page two of the appropriate form for appropriate documentation to support your requested change.
Take new passport photographs if your passport was issued more than 90 days ago. The photos must be identical, 2-by-2 inches, full face, front view with a white or off-white background. If you wear prescription glasses or religious garb on a daily basis those items should be worn for the picture.
Mail your Form DS-82 or Form DS-5504, your valid passport, the supporting documentation, and the required fee if any to the address listed on the application form. If your passport was issued less than a year ago, there is no fee. If it was issued over a year ago, then the fee as of January 2011 is $110.