One thing I have easily learned in my 4 years of the working world already.
No one EVER wants to hear concern. No one wants to hear you can't do it. I've been handed shit like I am just like "WTF how the fuck do you expect me to do this and make anything useful out of it?" The end result? If I throw some shit together confidently I look good. If you try to RIGHTFULLY explain anything such as risks, uselessness, impossibility, etc... people get pissy.
With that said my point is simply this: Sell yourself. No, don't be bluntly honest. You don't just know shit, you FUCKIN know it. It's basically confidence, but it extends further than that. Semi hard to explain.
Also, wear a suit + tie. I don't give a shit what your excuse is, go to a discount store or some shit and get one with dress shoes. Anyone who says otherwise is just retarded.
Goodluck - let us know how it goes.