To use a Life Cykel promo code, follow these steps: First, select the items to purchase on the Life Cykel website. After browsing the site and choosing the items, proceed to the checkout page. On the checkout page, there will be a field where the coupon code can be entered. The code is then applied to the order. This process helps to apply the discount to the purchase. Remember, each promo code may have its own terms and conditions, so it's important to read them before applying the code.