To adjust the quantity and frequency of your Autoship items, first visit the "Manage Items" tab on your Autoship page here.
Next, click the tan button with the circular arrows under the item(s) you'd like to adjust.
Here, you can edit the quantity, frequency, and next ship date of the item. You'll be able to choose to have the item included in your Autoship order every 1, 2, 4, 8, or 12 weeks. Be sure to click "Done" to save your changes.