Apply Your Skills
Before the interview check out the job qualifications that were listed on the advertisement. Compare those job essentials and expectations with your own attributes and skills. During the interview, focus on these key elements and express to the interviewers how you're a perfect fit and have those necessary qualifications. If you can give specific examples where those qualifications were used then let them know.
Chances are the interviewers already know that you're qualified however they want you to explain how those qualifications relate to real-life experience and how you handled the situations.