a. Write a letter to this effect to the assessing officer under whose jurisdiction you have made the PAN application (AO code). The letter must contain details such as your firm name, contact details, details of the PAN card which you need to surrender, reason for cancellation, etc. Keep the acknowledgement copy of this letter filed by you with the I-T department, which is sufficient as proof of surrender and no additional confirmation from the I-T authorities is required.
b. Manually Fill the Form No. 49A for change/Correction in correction in PAN and submit the same at your nearest UTI pan centers or NSDL TIN Facilitation centers mentioning PAN No. which you need to surrender at item no. 10.