Swapping mech pre-orders?

Considering the new mechpack info dropped last night, and that i've already pre-ordered the Uziel, MKII and Annihilator, would it be possible for me to ask customer support to "transfer" a pre-order?

In Lehmanns terms, I want to swap the Uziel out for one of the newer releases, and considering the highest price point is £/$20, I kinda figured that it'd be easy for me just to swap the contents easily.

.......Or do I have to go through the process of cancelling the order, reaffirming I have the cash back and then purchasing the new mech?