I haven't payed yet (paypal). Can I change my order (chose wrong shipping)

Hello!
Just placed a big order and then I logged on with paypal.
Before clickin "pay" I noticed the shipping choice was'nt the one I wanted.
I've recieved a "thank you for shopping" -mail from hobbyking but I have'nt payed yet.

I can't find any options to change or redo this order. Can you help me?

Thank you/Carl