Respected Sir,

I want to take advise on my birth date that is written on Leaving Certificate & origional birthday certificate. On my L.C. my birthdate is written 30/06/1987 & my original birth date is 30/09/1987. What can i do to make my original birth date is 30/09/1987? because in my passport my birth date is 30/09/1987. How to correct my L C. Please give me advise what to do?