You can always use the 'quick and dirty' method too. Open the image, then use image > Adjustments > levels. Then go to 'history', click on 'open' this reverts the image to it's original state, then choose the history brush, click next to, not ON 'levels' and paint away to your hearts content, returning the 'leveled' colour to the subject. Like I said quick and dirty, but it works ok. i never really use shadow/highlight.