If the I-140 petition is still pending, then USCIS needs to be notified in writing of the change. If the I-140 is already approved, then an amendment needs to be filed by the successor-in-interest petitioner. Note that the successor-in-interest petitioner must take over the rights and liabilities of the earlier petitioner, including the immigration matters. Successor-in-interest cases can be tricky and generally need to be addressed by an attorney. For additional details, please see the attached USCIS memo from August 2009.