To delete a task, perform the following steps:
Click Tasks from the calendar toolbar.
A list of tasks appears with a minimal set of attributes. If your task does not appear on the list, you can search your tasks by typing the search attributes in the search text field. To know more about how to Search Tasks, see How Do I Search for a Task from My Calendar?
Click the delete icon located to the right of the task, under the Status column..
A dialog box appears prompting for a confirmation on the delete action.
Click Delete.