Navigate to the Classes page. Select the Program, then the Class. Click on the pencil icon.
In the window that opens, under the "Basic" heading, will be an area where you can add an image. The image must be in JPG or PNG format.
NOTE: The image will be in a SQUARE shape. The original image does not have to be in a square, but it will show up as a square when you upload it. At this time, this cannot be changed.
To remove the image, just click "Remove Image." Be sure to save!
This image will show up on the Browse Programs feature similar to this: