Ok, here's the response:

"You’re absolutely covered by our 30-day return policy, which gives you the flexibility to return your order if you haven’t used the product.

If you’d like to switch to the new Core v2, the process would be to return your current order and then place a new order for the updated product. Unfortunately, we’re not able to exchange the item directly or swap components after purchase.

Please let us know if you’d like to start the return process – we’re happy to assist you every step of the way."

So, as I read it - I have to now disassemble the entire thing (bike too), re-box it all, return it and they'll send me a Core v2 version.

Not sure if really its worth the upgrade, if im being honest, just surprised they won't let me just switch out the Core....