You can lower the stings in multiple ways, though I'd advise you to have it done by a professional. Trying to do it yourself can lead to damage and may likely get your guitar intonated wrongly. The string height can be adjusted in three different places: the bridge saddle, the nut at the head and by adjusting the truss-rod (if your guitar has one; it's a metal pin that runs through the neck, stabilising the entire wooden neck).
Usually the best way to go about this is to adjust the truss-rod so that the neck is straight (it might simply be curved slightly, thus increasing the action on the strings) and if that doesn't yield (enough) results, you can resort to filing out the bridge saddle and/or the nut. Again, I'd advise you to have a professional do this if you have no idea where to start. It's not really a difficult operation, so this can't be expensive. You definitely don't have to get a new guitar!