Change in partnership firm

A partnership firm was formed with two partners with equal share of profits. One of the partner deceased the other partner wishes to continue the business and hence wants to add another partner. Do we need to create a new partnership deed or add an addendum to the existing deed? In case we need to form a new deed then do we apply for a new PAN and surrender the existing PAN The addendum is to be passed on a stamp paper ? The addendum is to be signed by both the partners and the stamp paper shall be bought in the name of the firm and the new partner or the individual partners Kindly share your inputs on the above query