To edit or view your custom product once it is in the cart, select the trash can icon to remove it from your cart.
Now, click your name in the top left and choose MY ACCOUNT.
Once you are in MY ACCOUNT, then select My Custom Products.
Now, you will be on your My Custom Products page and you will see a preview of your products. The last product you edited will be on the top. Click Edit to return to the designer and edit your spine to add it to your cart again. If you do not want to edit your custom product, you still must click Edit to proceed to checkout.
If you see View Cart instead of Edit (liked below) this means your product is still in your cart and you need to go to step 1 in these instructions to edit your custom product.