How do I delete an ongoing program?

In the app :

In "Programs" click on "Edit" button located on the right side of the ongoing programs.

Click on the red button with a cross that appeared above the program you want to delete. 

In the website :

In the "Meditation" tab, click on "Edit" on the right of the ongoing programs as shown in the screenshot below.

Then select the program you want to delete by clicking on the small red button.