Issue With Missing Surname In Official Documents – Need Guidance

My passport only has my first name (e.g., “ABC”) and no surname. This is now a problem as some countries require both for visa applications. None of my official documents (Aadhaar, PAN, 10th certificate) have a surname—this likely started in school and continued across documents. I do have a family surname and want to update all my documents to include it. My office ID already shows both first name and surname. I understand I may need an affidavit, newspaper publications, and my 10th certificate for the passport (I'm non-ECR). But I'm confused: Where should I start? Do I update Aadhaar or 10th certificate first? What’s the step-by-step process to get my name changed across all documents? Looking for guidance on how to proceed smoothly.