Step1: Choose the template and get into the builder.
Step2: The 5th tool of the toolbar at the left corner of your page reads 'Image/video'. Click on it and you will be provided with the image gallery where you can choose from. Also, you are free to drag and drop or browse an image.
Step3: Choose the image and click on 'Insert Image'. With this, the chosen image will be added to your page.
Step4: As soon as you click over the inserted image, you get a toolbar at the right corner of your page to manage image settings. At the top, you have an option to change an image.