Surname in Passport

I have only "Avinash" in all my marksheets. In passport, I have my surname as blank. I wish to know the following things:

1. How to change my surname in passport? The rules and regulations in Passport guidelines are for marriage and for women.

2. Will I have to change all my marksheets if I change my surname in passport? Will having different names in Passport and Marksheet create any problem?