When using a template in the Guided Editor Mode, go to the Edit step (step 3):
  1. Hover the cursor over the block where the image is.
  2. You will see three icons in the upper left corner of the enclosing box: Edit, Move and Delete.
  3. Click Edit or click directly inside the box to open the Edit Contents window.
  4. Click on the image and key in Delete on your keyboard to remove the image. If you want to change the photo, click the Insert/Edit Image icon that looks like mountains with the sun above and choose one.
  5. Click Update when done. 
When using a template in Advanced Editor Mode, where there are no guided blocks of content, click directly on the image and key in Delete on your keyboard to remove the image.