Remove the leaves from the vegetable. Keep the firm core in place for structure to make ricing easier.
Hold the base of the cauliflower in one hand and scrape the cauliflower against the larger holes of a box grater in an up and down motion, just like you would grate a block of cheese. Continue to rice the cauliflower into smaller pieces. As you get closer to your hand, move to a new area of cauliflower, so as not to cut your hands. Use caution. Avoid ricing to the firm core of the cauliflower.