Editing - Curves

This is a before and after shoot of a photo. The photo on the left is before the levels are changed and the one on the right is after they have been changed. 

Step 1 - Go to Layers, then to New Adjustment Layer and then Curves

Step 2 - This box will appear then click use previous layer. 

Step 3 - This screen will appear move different parts of the curve to get the desired effect on the photograph 

Step 4 - Once the desired effect has been achieved press the double arrows on the small levels screen to close the screen