Update in mothers surname in the minor child’s passport

Hi The passport of my son age 16 years is due for renewal. His biological father is deceased . I have remarried . The update is required due to following reasons : 1. Validity to expire in six months 2.change in the surname of mother due to second marriage 3 . The passport of son does not have biological father’s name and the passport is made on my behalf as single parent with my maiden name I.e Shivani sharma 4 I updated my passport after remarriage with new surname and spouse name in it .(Shivani Gupta ) 5.Minor son passed 10th class 4. The school 10 class certificate and the birth certificate is in my first name Shivani (no surname ) along with biological fathers name 5 the other documents like Aadhar ,pan, driving licence , bank accounts are in my maiden name Shivani sharma except the passport which has new surname Shivani Gupta in it. I have a news paper cuttings specifying the change of name . What else documents do I need for the renewal of my sons passport ?Kindly guide Thanks Shivani