Changing or removing the image-based ads or carousel images is made simple by visiting the Theme Settings section in the admin panel. Browse your computer for an image.For best results, stick to the recommended image dimensions. 

Images used in ads and the homepage carousel can include an optional link to another page in your store or elsewhere on the internet. Copy the full URL from the page you wish to link to (for instance, "http://www.shopify.com/") into the text field labelled "Link to" on the Theme Settings page.

Don't forget to click "Apply Changes" at the bottom of the page when you're finished. 

Carousel Image Dimensions

The image carousel requires specifically sized images. By default this value is 710×255px. Images smaller or larger than the defined dimensions may result in unexpected cropping. Only the height of the carousel is adjustable in theme settings, but the width can be changed by modifying style.css.liquid from the template editor. 

Ad Image Dimensions

Ad images are slightly more flexible than images used in the carousel. They do not require a specific height, but to maintain a consistent look and feel, should stick to the recommended dimensions. Failure to do so risks disrupting the design of your store. 

Resizing Images

There are free online tools you can use to resize and crop images, if you don't have access to a designer or Photoshop. Such tools include  Aviary and Piknik, among others.