You can edit a task from the My Day, Calendar, or Tasks applications.
From My Day:
    1)  From the Task List section, right click on the task.
    2)  Select Edit Task. 
From Tasks:
    1)  To Edit a task from within the Tasks application you have 2 options: 
             a.  Right click and select Edit Task. 
             b.  Double click on the task and the Task menu will appear. 
From Calendar:
1) Right click on the task and select Edit Task.
Related Links: 
    - Task Status
    - Task Priority 
    - Set Due Date
