It is fairly easy in lightroom, just use the CA slider to adjust the lightness, and color. Even though the best method is to use PhotoShop. Zoom in on the color of the CA, select and match said color and desaturate untill it blends. In lightroom, there is a very good tool for fixing vignetting again on the sliders marked vignetting just adjust to eithier light or dark (opposite) to fine tune your photo.