Thank you for the response!
Yes I had a look at that tutorial before, but If I understand it correctly it's about modifying or customizing checkout fields.
What I'm trying to do is ADD billing_first_name and billing_last_name fields to woocommerce registration form. (In woocommerce account page, so that during registration first and last name would be collected)
https://dl.dropbox.com/u/2655364/wc-add.JPG
I'm trying to add the two checkout fields (billing_first_name and billing_last_name) in the registration form where the arrows are.
am I missing something very obvious here? :)