To delete an item, change the quantity to zero and click on "Update Qty". To change the quantity of an item, change the quantity to the desired number and click on "Update Qty". If you've used a credit card with previous orders, then just select "on file" in the appropriate check out box and we will use the card number on file. Only enter the credit card number again if the information or expiration date has changed. If you feel nervous about placing your order online, feel free to call 1-888-88-SYNTH to provide your information (435-563-0409 outside the USA).