You can edit the volunteer event that you created by following these steps:

 

To edit the volunteer event - 
  1. Click on the Class name in the left navigation tray
  2. Click on Signups in the Updates tab
  3. Click on the Volunteer Event you want to edit
  4. The Volunteer Event details screen is seen
  5. Click Options in the top right corner of the volunteer event
  6. Click Edit 
  7. You will be given an option to modify the names of items/tasks and/or quantity
  8. After editing, click Next
  9. You can edit Title, Location, Notes, Event Start Date & Time, Event End Date & Time
  10. Click Save



For more information, check out the following articles:
Requesting Volunteers for Recurring Tasks in Class

Requesting Volunteers for My Class Event

Signing Up to Be a Volunteer
Canceling My Volunteer Sign Up
Asking a Question on a Volunteer Task
Assigning Parents to Volunteer Tasks