SEBI SAST disclosure - Buying huge quantity of a stock in CNC - How to file, etc?

When buying 5% or 7%, or 9%, and do on up to less than 25% of the total shares of a company, disclosure need to be made to SEBI. [1] [2]

The same needs to be done when 2% or more shares are sold. [1] [2]

Kindly guide a beginner retail investor as to:

Q1. When will I file, the day I trade or T+2 day when I receive the stocks in my demat account?

Q2. If I buy overnight CNC futures of the stock and hold till expiry, when will I file - on the expiry day or when I receive the stocks in my demat account?

Q3. How to file the disclosure as a retail and individual trader?

Do we do it by ourselves online, a broker, a chartered accountant, or the company’s RTA?

Q4. Any other paperwork, regulation, laws required to be complied with after acquiring substantial shares of a company?

Thank you

[1] SEBI Takeover Code - YouTube
[2] SEBI | Securities and Exchange Board of India (Substantial Acquisition of Shares and Takeovers) Regulations, 2011 [Last amended on December 06, 2021]]