The meeting name, notes, and action items are all editable. Simply select the text in an action item or the notes to make changes. The meeting name can be updated the same way.
You can also select the assignee to reassign an action item or add an action item that came up after the meeting.
To make edits before the meeting notes get sent out via email: turn off automatic invitee emails from settings, make any necessary edits, then select Share to email the meeting notes manually.