Splitting Given Name to Surname- Indian Passport

Hello! My passport has given name “xxx yyy” and a blank surname. I’d like to split the name and renew my passport with Given Name: xxx and Surname: yyy Could someone please help and provide the guidelines for this? Is an affidavit required? If yes, how can it be filled out correctly? Sorry, I stay outside India and hence less resources to guide. Thanks in advance!