Simply by amending in next month gstr1... Through amendments column... That is just like revise return... I am just saying that if u hv not done at ur level then ur buyer has also the option in future so u can't escape... So better make today
When u r amending ur gstr1 then invoice is uploading date waise.... It is automatically reflected in gstr2a in respective month of buyer... When u file next month gstr1 through amendments... So don't worry