maiden name and married name on my SS card

When I was married at age 18, my name was changed to my first name, maiden name, and married name... The social security ofc dropped my middle name off my card and replaced it with my maiden name. Since I didn't get a new card, I didn't know this until now -- 37 years later... On all my legal documents I go by my first middle last name... How do I add my middle name and removed my maiden name as my middle name? What documents do I need to bring with to the SS Ofc to get this change?