Because we want to keep a transparent audit trail, we don't delete any payment information or allow it to be edited.
If you need to delete a fee after you've entered it, enter a payment transaction in the same amount; this will reduce the balance to zero.
Similary, if you need to delete a payment, add a fee of the same amount, which will reduce the balance to zero.
We suggest you add a comment in the 'Notes' field to indicate that these are corrections, not real payments.
If you need to change the amount, rather than delete entirely, then do the same but change the amount so that the remaining balance is correct (e.g. if you entered a fee of $100 but meant to make it $80, add a payment for $20 and the remaining balance will be $80).