Use our Edit Multiple events tool to edit or de-activate multiple events:

You'll find the tool under the Events menu.

In the top set of boxes, select the properties of the existing events you'd like to update.

In this example, we're matching Dinner Cruises on Saturday and Sunday, between May 1 and June 30.

In the second set of boxes, indicate what properties you'd like to change on those events.  

In this example, we're going to block those weekend Dinner Cruises from the public and have them start 15 minutes later than usual.