I would consider trying a BoxCox transformation if I were in your position. Better explanations for this are provided elsewhere - http://stackoverflow.com/questions/33999512/how-to-use-the-box-cox-power-transformation-in-rhttps://stackoverflow.com/questions/33999512/how-to-use-the-box-cox-power-transformation-in-r.
Failing that, the most common transformations are power and logarithmic transformations (depending on the current type of skewness).