See the topic Recalculate to learn about the Recalculate Options available when recalculating financials for Event Attendee Registrations.
You can access the Recalculate command for an Event Attendee Registration under the Registrations tab of the Event Attendee edit form.
Figure 360: Recalculating Attendee Registration
If you open the Event Attendee Registration edit form, you can also access the Recalculate command in the top ribbon.
Figure 361: Recalculating Attendee Registration from Edit Form