Click on customize option on the top bar, and click on the edit icon of the section of image which you wish to change. A left sidebar with customization options will appear, click on the select image button and then upload your image. You can crop your image if required or else you can skip cropping. Finally, your image is replaced successfully.
Note: We fixed all the image sizes to display images correctly as shown in the theme. Please don’t crop the image, if you want to crop then make sure it should not exceed more than 20px around. For better results don’t crop the image, just select the area of the image by moving.