Cancellation/Surrender of PAN No.

The best part there is a procedure for cancellation of PAN in this link

https://www.tin-nsdl.com/faqPANcancellation.asp

The worst it is applicable only if you have two PAN's. In short there is no procedure as such of cancellation of PAN.

But now u have a firm which is dissolved and hence is no longer in existence. Hence file a letter for cancellation of PAN with your A. O. and also send a copy of the same with the NSDL for cancellation of PAN.

Otherwise ask your A. O. what can be done to cancel a PAN.