Note: In this example we are ending a weekly recurring task that occurs on a Friday.
Step 1: Navigate to Scheduled Tasks and select recurring Task you wish to end
Step 2: On the Task flyout select Edit
Step 3: Select The entire series
Step 4: Select end Date then Save
Scroll down to the bottom and select a date you wish to end task and when happy go to the top and select save.
To check your task is no longer recurring select Show on Calendar.
As you can see below, the final task shows the end date chosen.
The task is now removed from the Calendar if you check the tasks the following week.