Can we update the default Workflow Mailer Notification template? (specific field)

In the PO workflow mailer, as by the default, the PO 'Need-by-date' is shown on the line details. It was requested by the approvers to either change the default to 'Promised-date' instead of 'need-by-date' or add both on the line details as shown in the attached document.

Appreciate your kind feed back.