In some weired sense (believe it or not) I have faced that situation....where I was at the receiving end....
TWO TIMES
One happened in school and one happened in one of my previous working places. ..Both of these girls (which I never knew even existed in this earth) just came up to me and point blank told me that they are in dire love with me
It was quite SHOCKING at first..and funny in retro aspect as well
Well, I didn't turn both of those girl off. I appreciated their sheer guts to go out of the norm and say that directly to me. Of cource I made my self obliged to go out with them for couple of times and found out that both of them are non of my type.
So, all ended in a friendly manner without hurting anyone. Both of them are still good friends with mine
BUT--------------------
As for you mate... I don't think the GIRL would take it that much obliging as I did. They would just throw you off without battering an eye or think you are a total loony toon.
Girls in majority like to see or prefer a man who's solid in his stance and unmovable with a rigid self value. So, I advice you NOT TO go begging behind.
Talk to her first as a friend if you can.. and see if she's your type.. if SO, then it's time to grit your teeth and take a chance for the better or worse.
I advice you thoroughly not to take her by SURPRISE. Slow and steady would be an ideal method to follow if you are looking for a long lasting relationship.
Just be your damn self.

cause pretending won't help much and you can't ACT for the rest of your life.. and when she feels / finds out that you are NOT the man she liked earlier.. there's a great chance of heart breaks and even a breakup.
So.. Be your self and go for the Kill.. (slowly..if you are REALLY interested in her)
or else, just tell her.. if she says NO ... spend a few bux and get a more good looking chick to bang you.. take some pics.. email her with a "FUCK YOU" line (that idea was a kind courteous gesture from my good friend / colleuge who is just giggling right beside me...telling me how he actually DID it to a girl once he was interested in)