Resizing a JPEG image is easy and can be done in just a few steps. First, open the image you would like to resize in an image editor such as Adobe Photoshop or GIMP. Then, use the crop tool to select the area of the image that you want to keep intact while resizing it. Once you have selected this area with your cursor, click on Image in the top menu bar and then choose either Image Size or Canvas Size, depending on which program you are using. With Image size, you can enter exact pixel dimensions for your desired width and height; with Canvas size, you will be able to specify how much extra space should be added around the edges of your photo. After inputting these values into their respective boxes, click OK and save your changes - voila! Your JPEG image has now been successfully resized according to your specifications!