Transfer from Oxford?

<p>Hi there! I'm currently a first year international undergraduate at Oxford but I'm not enjoying my time there now and would really like to transfer to Dartmouth (which was my first choice to start with but i was rejected for ED last year).
I'd like to know how hard (and what the chances are) it would be to transfer from the UK system and whether it'll still be possible to graduate in 2014 if i take summer classes like crazy?