How to delete surname in academic certificates

Since you have changed your surname in Aadhar Card and PAN Card and a notification has been published through the gadget, it would not be difficult to follow the the gadget.
What is needed at this juncture is to write an application to the the concerned authority of the Board regarding deletion of your surname with the latest photocopies of Aadhar Card and PAN Card as an evidence of omission of your surname through the court. If you could go through the proper channel involving your Principal to forward your application, it would be more effective. You need to enclose a demand draft of the required amount for this purpose. Your registered envelope should accompany an acknowledgment card where the concerned authority would sign on receiving the application. This would be the ocular proof of your submission of your application. Hope this will resolve your issue.

The general procedure for change of name in your certificates is to contact the school in which you have studied and from there you have to see that your application is forwarded to the board.
You have to go to the school in which you have studied your SSC and then make an application asking for the change in the certificate. You have to attach attested copies of the Gazette publication, affidavit copy, newspaper publication copies, Revised Aadhar and Pan card to the application and the same is to be submitted in your school, They will verify the records and then forward to the board for necessary changes. Then the board will do the same and send the same to the school and the school will hand over the certificate to you. The school will let you know whether you have to pay any fees.
You can continue even with the present certificate and you can manage by attaching a copy of the gazette certificate so that there will not be any problem.

If you are belonging to to the states other than Tamilnadu and Kerala, surname, village name or family name are most important and cannot avoided once issued. To this when you are giving your name/father's name before issuing or at the time of registeration without surname.
If you are very particular to have your name without any surname/village name/family name, you can make an affidavit through a local advocate and get the same signed by a notary public advocate.

The purpose of gazette notification and name change affidavit is to prove that your present name is your actual name and whatever name is reflecting in the old certificates and credentials is not correct. You have already achieved that purpose by changing your name in Aadhar Card and other important documents and you have a copy of gazette notification with you which entitles you to continue with your present name in all the future documents and as well as in the document verification sessions which you are expecting in the future. So, I do not see any need of changing your name in the old certificate. Many people go through this exercise of name change but they don't go for change in the old certificates. That will not serve any fruitful purpose. If you still feel that you require a new certificate from the education board where your name is now corrected as per the present affidavit and other notification then you can very well approach the school and pay the requisite fee and in due course of time they may provide you the new certificate in which your name will be corrected accordingly. Remember it is and old document and they will not be doing it so easily without all the proofs to be submitted by you in that matter. Even if they issue it, it will be issued as a duplicate one given as on today and it will be mentioned that this certificate is being given in accordance with the name change and gazette notification which the person has achieved through the affidavit and gazette notification route. So even if that new certificate issued by them, it will not be useful without the copy of gudget notification and affidavit. In my view that exercise is not needed.

You have already changed your surname in the adhaar card and PAN card. And now you want to change your name on the educational certificate. So, you will have to fulfil certain formalities. You should contact the school from where you have passed SSC. You should write an application regarding changing your name same as on your PAN card. Your application will go through the proper channel for making necessary changes. Hence, you should attach the adhaar card and PAN card along with the application and submit it to the school office. There may pay the requisite fee as a demand draft. The school authority will forward it to the board. Board will do the necessary changes in your name as per your requirement and then a fresh copy of the certificate will be sent to the school office from where you can collect your new certificate.