Change the rotation of the sprite, using degrees. 0 degrees is to the right. 90 is up. 180 left, 270 down. But, if your sprite was drawn facing up, then rotating it 90 degrees will have it pointing left. The angle goes counter-clockwise. The image will be scaled such that it continues to fit within the rectangle that it was originally in. This results in a little bit of shrinking at times, but you should rarely notice that.

public int Rotation { get; set; }