Spitty:
In the confirmation email they sent you with your customer number and order number, there should be a link to the right of your order number to a form so you can change your order.
if you check Your online account, there should also be a link around there too.
Now when you ask to change specs, they cancel your previous order and issue a new order number, putting you in the back of the line again (which is what happened to me, twice).
Good luck, and watch out for pricing. I was overcharged and had to call to get it fixed.
D
Edit: I just called order status, and even though my order was placed today, it's already in Production - Building stage. That was darn fast.