1. Go to Financials | Search Payment | Select Payment, a new Edit Payment window will open.
2. You can now change the Transaction Date or add Internal Comments if the Payment was created in the last 7 days. If the bill was created more than 7 days ago, only the Administrator can modify these fields.
If you need to change the Paid Amount, that cannot be done here. You will have to Cancel this Payment and create a new one with the correct Paid Amount.