With this information I had to:
1) Book an appointment with the American Consulate in Belfast
2) Pay for the appointment
3) Gather any relevant documentation for the interview.
The nearest appointment was a month away so I booked mine for 7th August, to receive a frustrating email a week later informing me that the consulate had decided to close that day and that i must reschedule another appt which happened to be 18th August.
Word of warning make sure you book your appt ASAP as the appts fill up very quickly!