Can ewb value modified in gstr1 after delivery of goods

Dear sir ,
I have following query regarding E Way bill

I issued a debit note to supplier of Rs.80,000(inc. GST) the same value mentioned in EWB and same uploaded and filed by me in GSTR1 .
 but now on receipt of goods the supplier is refunding only 50% value of the debit note that is 40,000 (inc. GST amount ) . Can I amend debit note in GSTR1 by reducing amount and tax value which will be different and less from the amount I mentioned in EWB .