These docs are for an old release.
Info on upgrading to v4
removeEvents
Removes events from the calendar.
.fullCalendar( ‘removeEvents’ [, idOrFilter ] )
If idOrFilter is omitted, all events are removed.
If idOrFilter is an ID, all events with the same ID will be removed.
idOrFilter may also be a filter function that accepts one Event Object argument and returns true if it should be removed.