There are a few ways to pixelate an image in Photoshop. The first way is to use the Pixelate tool. This tool can be found in the Tools palette, and it allows you to pixelate an image by selecting a color and then pressing the Pixelate button. The second way is to use the Clone Stamp tool. This tool can be found in the Tools palette, and it allows you to clone an image by selecting a color and then pressing the Clone Stamp button. The third way is to use the Freehand brush. This brush can be found in the Brushes palette, and it allows you to create freehand images by selecting a color and then pressing the Freehand brush button.