The Central Government vide Circular No. 07/2017 dated September 01, 2017 has clarified that if a registered person intends to amend any details furnished in FORM GSTR-3B, it can be done through the FORM GSTR-1 or FORM GSTR-2.
Read more at: http://www.cbec.gov.in/resources//htdocs-cbec/gst/Circular%207_7_2017.pdf