how to change mobile number and Email ID

Sanaa...Tulip... (student) (186 Points)

01 October 2017  
How can I change authorised signatory mobile number and E-mail id with the same taxpayer's details.. As I am doing so but same pan can't be used twice...So if I Delete old one then it doesn't allow to delete old one Authorised Signatory which is sane person only mobile number n I'd is changed...