It's really easy using store credit.
After clicking 'Place Order' on the cart page, you will be directed to the 'Customer Information' page. Just fill in the discount coupon code sent to you via email in the field given (on the right) and click 'Apply.'
If you have two or more store credit coupons that you would like to use or if the product you'd like to purchase costs lesser than the coupon value, simply contact us below and we will help you out!