Related to changing DOB in CBSE Marksheets by relying on Birth Certificate

Please NOTE = Kindly answer the questions below, I have gone through a lot of related judgments from CaseMine website but I am still confused. I would appreciate if you could kindly answer all of these; even if it is just a few sentences, that would be okay. Issue is this = My DOB is different in Birth certificate. But I have documents like CBSE (X XII) Passing certificates, Aadhaar, PAN, Bank, Voter-ID and even Passport; all of these documents have same DOB. There is a mismatch with Birth certificate. I plan to do masters and then settle abroad. So, it might be an issue at some point. Since Birth certificate is treated as the Actual DOB as per law. So, I will have to get all others changed. Rest of the documents are easy to updated online, only CBSE requires Court Order. So, for this what is the correct procedure = At some places, it is mentioned as - File a Civil Suit in the District Court and at some places, it is mentioned as - File a Writ Petition in a High Court? Which one is better and less time taking? I am from Haryana, which High Court should I approach - P&H or Delhi? Though pendency is lesser in Delhi HC (checked from LiveLaw article about Parliament Questions on Pendency), will I get faster hearing in Delhi HC. If I file a Writ in Delhi High Court, what is the approximate legal fees, lawyer fees and all charges I can expect. Is it possible to get it done without lawyer, as a petitioner-in-person. I can do research about the precedents but not sure about exact procedures and rules about Drafting and filing. Any tips or tricks to save money?