Contact the registrar's office at the institution where the diploma was originally issued. Ask about their procedures for obtaining an official copy of your diploma. You will likely be instructed to obtain the proper form by mail, in person, or online.
Fill out the diploma copy request form completely. Any change of name requests must be accompanied by court documents, or a marriage license, and may have an additional cost associated with them. Request multiple copies at once, if possible, to avoid running out.
Make a photocopy of the original diploma, if it's available. Submit the diploma copy request form and the photocopied diploma to the registrar's office. Some offices require a payment for each copy requested.