I can't think of anything that could make it easier.
It's not like, she's cheated on you, or you've been drifting apart, or your or her priorities have shifted...you're separating whilst in love. The only reason for it is your respective choice of university. Although I speak from no experience, I can only imagine how painful it will be... it will take a long time to get over her; you'll miss her, etc etc. It'll always feel like you're together due to the circumstances of the "breakup" and you may end up feeling guilty if you ever start liking someone else when you get to uni.
Good luck.