Wordpress site registration form modification

Our wordpress site is based on this premium theme. [login to view URL] This is the registration form. It is responsive. [login to view URL] Basics. The site currently allow users to register with their Facebook or the registration form. But in this modification we want the two options to be used together as described below. Your task is to modify this registration form to take two steps. Step 1. Members register by filling in the registration form. [See [login to view URL]] 1a. Member verify/activate their email (Once email has been activated, member is redirected to link their Facebook.) Step 2. Member link their Facebook profile. [login to view URL] NOTE: Member cannot enter site unless the steps have been completed. Member who do not activate their email are always redirected their upon login. Once member activate their email, they are always redirected to link their Facebook. They cannot proceed to site otherwise. Linked Facebook profile: 1. When a user linked their facebook account, we need to fetch their profile url and profile photos. This usually works already. members cannot edit nor see their Facebook linked url once linked it is only at the admin backend. (This usually works already.) Security checks: Make sure no spam bots are able to register or bypass the registration process.