Two main routes await your document-wielding hand:
Ministry of Foreign Affairs Foxtrot: This classic path involves a visit to your nearest Ministry of Foreign Affairs office. Pack your original document, a photocopy, and the requisite fees. Processing times can range from a siesta or two to a couple of weeks, so plan accordingly.
Embassy Tango: If you're already twirling in Spain, the Spanish Embassy in your home country can be your knight in shining armor. The process is similar to the Ministry route, but with the added convenience of being on Spanish soil. Spain Apostille