Firstly, you have to prepare an affidavit (Notary) bearing the changes, then inform your employer of the changes by enclosing an attested copy of the same affidavit. For EPF, fill Form-2 (Revised) with amended details duly attested by the employer and submit the same to EPFO. For gratuity, fill the revised Form-F and submit it to the employer. Lastly, coordinate with your HR Department as they will formalize all the necessary formalities.
Thanks & regards,
Sumit Kumar Saxena