Log into your profile and go to your business details page. Click on the "Edit cover" photo button on top right:
To fit within this section, your cover photo will need to be a landscape image, which is a minimum of 1440 pixels by approximately 366 pixels.
Unfortunately, we are unable to resize images. However, you can edit your image with a photo editing software, such as Microsoft Paint.
For more information on uploading a cover photo please click here: